Tag Archives: obesity

American diets consisting of even more ultra-processed foods than thought

Heart disease is one of the largest killers in the United States. (Photo: Pixabay)

Let’s face it, Americans have never been famous for their healthy diets and slender physiques. Now a new study out of New York University published in the American Journal of Clinical Nutrition has found that the diet of the average United States citizen is including more ultra-processed foods than ever.

Ultra-processed foods are defined as industrially manufactured, ready-to-eat or heat foods that include additives and are largely devoid of whole foods. These ingredients form an equation that leads to obesity and heart disease.

“The overall composition of the average U.S. diet has shifted towards a more processed diet. This is concerning, as eating more ultra-processed foods is associated with poor diet quality and higher risk of several chronic diseases,” said Filippa Juul, an assistant professor and postdoctoral fellow at NYU School of Public Health and the study’s lead author. “The high and increasing consumption of ultra-processed foods in the 21st century may be a key driver of the obesity epidemic.”

The study looked at 41,000 adults who took part in the Center for Disease Control and Prevention’s National Health and Nutrition Examination Survey from 2001 to 2018. The survey asked the participants about their diet in the previous 24 hours. Despite movements to decrease intakes of processed foods and transition to a diet with more whole foods, the results didn’t appear to show any such trend towards healthiness.

Ultra-processed food consumption grew from 53.5% of calories at the beginning of the period studied (2001-2002) to 57% at the end (2017-2018). The intake of ready-to-eat or heat meals, like frozen dinners, increased the most, while the intake of some sugary foods and drinks declined. In contrast, the consumption of whole foods decreased from 32.7% to 27.4% of calories, mostly due to people eating less meat and dairy.

Processing food changes it from its natural state. Processed foods, for the most part, only have two or three ingredients. They are also essentially made by adding substances such as salt, oil, or sugar. Examples include canned fish or canned vegetables, fruits packaged in syrup, and freshly made bread.

Some foods go a step further in their unhealthiness. These are highly processed or ultra-processed foods. These most likely have many added ingredients such as added sugar, salt, fat, and artificial colors or preservatives, as well as substances extracted from foods, starches, and hydrogenated fats. They may also contain additives like artificial flavors or stabilizers. These are your frozen meals, soft drinks, hot dogs and cold cuts, fast food, packaged cookies, cakes, and salty snacks.

Juul says that one of the best – and maybe only ways – to improve diets is to implement policies to reduce their intake, such as revised dietary guidelines, marketing restrictions, package labeling changes, and taxes on soda. The political landscape being what it is, however, it would be a very curvy and pothole-filled road to implement any of those changes.

“In the current industrial food environment, most of the foods that are marketed to us are in fact industrial formulations that are far removed from whole foods,” said Juul. “Nevertheless, nutritional science tends to focus on the nutrient content of foods and has historically ignored the health implications of industrial food processing.”

The study didn’t see any correlation between income or ethnicity. The one outlier was Hispanic adults, who ate significantly less ultra-processed foods and more whole foods compared with non-Hispanic white and Black adults.

The study took into account diets pre-COVID-19, and Juul says that diets probably only got worse throughout the pandemic.

“In the early days of the pandemic, people changed their purchasing behaviors to shop less frequently, and sales of ultra-processed foods such as boxed macaroni and cheese, canned soups and snack foods increased substantially. People may have also eaten more packaged ‘comfort foods’ as a way of coping with the uncertainty of the pandemic. We look forward to examining dietary changes during this period as data become available.”

Obesity doubles the risk of COVID-19 hospitalization

Credit: Pixabay.

Being obese might be the single most important risk factor for the worst outcomes for COVID-19.

According to a review of more than 75 previously published studies that involved more than 400,000 patients, obese COVID-19 patients were twice as likely to require hospitalization and were nearly 50% more likely to die than non-obese individuals.

The more extra pounds, the higher the risk of severe disease

Even when scientists were still collecting the first data on COVID-19 patients early this year, it became apparent that obesity was a major risk factor. Not only does obesity tend to weaken the immune system, but it also is associated with diabetes and high blood pressure. However, it’s quite welcome to have all the results of dozens of studies that investigated the link between COVID-19 and obesity pooled into a single review. Unfortunately, the conclusion wasn’t encouraging for more than a third of Americans currently classed as obese.

According to the meta-analysis performed by researchers at the University of North Carolina, people with obesity were twice as like to end up in the hospital and 74% more likely to be admitted to an intensive care unit (ICU), compared to people in the normal weight interval.

Besides the fact that obesity is closely associated with diabetes and high bood pressure, both risk factors for severe symptoms of COVID-19, studies show that obesity causes high levels of glucose in the body. This affects macrophage and monocyte activation, increasing inflammation in the body. Past research has shown that macrophages from obese individuals are an ideal place for SARS-CoV-2 to thrive.

All the extra weight also puts more strain on the body’s organs and can impede breathing. Each of these individual risks adds up, making obesity one of the greatest risk factors for COVID-19, if not the single greatest one.

There are also concerns surrounding a potential vaccine for SARS-CoV-2, the coronavirus that causes COVID-19. The authors of the review caution vaccine researchers to be mindful of how a population with a high percentage of obese individuals might affect vaccine efficacy.

“The COVID‐19 pandemic challenges all countries enormously. Our systems, institutions, health and welfare will feel the impacts for many years. The high prevalence of individuals with obesity exacerbates the threat to everyone’s health, and the economic, social distancing and stay‐at‐home components compound the impacts. We will need creative solutions quickly to prevent undesirable dietary patterns and promote healthy eating, which is so critical to our future health and for building resilience against future threats,” the authors of the new study wrote.

Exposure to traffic noise promotes obesity

Living in areas with high traffic has several adverse health effects, mostly due to the air pollution generated by vehicles. But even the noise itself is pretty bad for your health, a new study reports.

image via Pixabay.

New research at the University of Oxford and the University of Leicester found that long-term exposure to traffic noise could be a promoter for obesity. People living in such areas had a higher chance of having an increased body mass index and waist circumference, the study explains. This effect was more pronounced in areas with louder traffic noise.

Heavy traffic

“While modest, the data revealed an association between those living in high traffic-noise areas and obesity, at around a 2% increase in obesity prevalence for every 10dB of added noise,” says lead author Dr. Samuel Yutong Cai, a senior epidemiologist at the University of Oxford.

“The association persisted even when we accounted for a wide range of lifestyle factors, such as smoking, alcohol use, physical activity, and diet, as well as when taking into account the socio-economic status of both individuals and the overall area. Air pollution was also accounted for, especially those related to traffic.”

The study worked with data from more than 500,000 people, data which it mined from three European biobanks in the UK, the Netherlands, and Norway.

The authors describe the identified link as ‘modest’ because they uncovered an interplay between traffic noise and indicators of obesity in individuals from the UK and Norway, but not in the Netherlands. By themselves, these results aren’t enough to reliably confirm a cause and effect relationship between the two. However, the authors note that the findings are backed up by previous similar findings in other countries in Europe.

Still, the findings can’t, as of right now, be used as proof that one causes the other. They do, however, offer enough evidence to warrant further research into the topic.

Over 100 million people in the EU live in areas where road traffic noises exceeds 55dB (decibels) in volume, which is the safety threshold set by the EU, the paper notes. This exposure could be a driver of obesity.

“It is well-known that unwanted noise can affect quality of life and disturb sleep,” says co-author Professor Anna Hansell, Director of the University of Leicester’s Centre for Environmental Health and Sustainability.

“Recent studies have raised concerns that it also may influence general health, with some studies suggesting links to heart attacks and diabetes. Road traffic noise may increase stress levels, which can result in putting on weight, especially around the waist.”

Most of our efforts to stay healthy and avoid the extra pounds only work on an individual level — think things like exercise or dieting. And we should definitely keep doing that, as they are still the most effective tools we have against obesity. But policies that reduce traffic noise (or at least, exposure to it) may help further tackle this issue “on a population level,” argues Dr Cai.

“As we emerge and recover from COVID-19, we would encourage the government to look at policies that could manage traffic better and make our public spaces safer, cleaner and quieter,” he adds.

“Air pollution is already a well-known health risk, but we now have increasing evidence that traffic noise is an equally important public health problem. The UK should take this opportunity to think about how we can, as a society, re-organize cities and communities to support our health and reap better health outcomes across the whole population.”

The team is now testing how exposure to other sources of noise, such as that produced by aircraft, influences weight gain.

The paper “Impact of road traffic noise on obesity measures: observational study of three European cohorts” has been published in the journal Environmental Research.

Being overweight is a major risk factor for COVID-19, says French chief epidemiologist

Being overweight places you at increased risk from the coronavirus outbreak according to Professor Jean-François Delfraissy, who heads the scientific council advising the French government on the epidemic.

As many as 17 million of France’s 67 million citizens were seriously at risk from the coronavirus because of age, pre-existing illness or obesity. He adds that these factors mean that for the USA, “where the problem of obesity is well known,” the prospects are particularly grim.

Image credits Michal Jarmoluk.

Obesity has been identified as an independent risk factor associated with both morbidity and mortality for influenza (i.e. it makes it likelier to catch the disease and die from it), and a study on Chinese patients has found an association between higher BMI and mortality risk. Out of 17 patients who died during the study, 15 (88%) were classed as being overweight or more on the BMI scale, while only 18 of the 95 survivors (19%) were classed as overweight or above on the BMI scale.

One of the possible reasons is the strain placed by obesity on the body’s immune system. Writing for Aljazeera, Dr. Amir Khan, an NHS doctor and a senior university lecturer in the UK, explains that a high BMI places strain on the body that affects the function of the lymphoid and neutrophil line. This can weaken our immune response and leads to a “low level of chronic inflammation of normal tissue”.

Obese patients are also more difficult to transport and intubate, and he believes that “most healthcare systems are not well set up to manage patients with obesity”.

“This virus is terrible, it can hit young people, in particular obese young people. Those who are overweight really need to be careful,” Delfraissy told franceinfo radio.

He added that around 88% of all patients who were infected with the virus only showed flu-like symptoms and that mortality rates among young patients with severe cases were low — about 2%. However, this rate rose up to 14% for at-risk groups.

The country is still a long way away from achieving herd immunity — the French government is aiming for 50% to 60% of the population to be infected and recover, Delfraissy said. Still, progress is slow. It’s still much too early to end the country’s lockdown, which started March 17 and is set to last until at least April 15. For now, the council’s recommendation is for strict confinement measures to continue for the foreseeable weeks. Pressure on the country’s intensive care units (ICU) needs to ease, and the spread of the virus must be contained, before such measures may be lifted.

“Initial data show that the number of people who may have developed immunity is lower than we imagined, about 10-15%,” he explains.

A third condition for ending the lockdown was having sufficient stocks of equipment, Delfraissy adds, notably masks, testing kits, and tools for tracing infected patients.

Little owl eats all the mice, grows too fat to fly

A seemingly-injured owl brought into the Suffolk Owl Sanctuary last week turned out to be fine — but “rather chunky”.

Image credits Suffolk Owl Sanctuary.

The little owl (Athene noctua) was brought in by a landowner who believed she was injured. The bird was found in a ditch, grounded, and in a “soggy state”. However, upon closer examination, staff at the sanctuary discovered that it was “simply extremely obese” rendering her “unable to fly effectively”.

Suffering from success

“This is extremely unusual for wild birds to get into this condition naturally,” the Suffolk Owl Sanctuary explains in a blog post.

The owl — which wasn’t named and is awaiting release back into the wild — weighed 245g when brought in. The sanctuary, based in Stonham Aspal, says this is a third heavier than a typical, healthy female little owl. She was placed on a diet over several weeks to shed 20-30g.

The sanctuary explains that she was “a rather chunky 245g”.
Image credits Suffolk Owl Sanctuary.

The bird didn’t have identification rings or chips, and none of the locals reported losing an owl. The staff monitored the bird for “telltale” signs of life in captivity, such as familiarity with certain types of food. The owl seemed to prefer wild food types (such as dark mice), so the team concluded that this is “an unusual case of natural obesity!”

“Where she was found is very productive land, and it’s been a mild winter and there’s a lot of food around — voles, mice. We think she’s just done incredibly well for herself and overindulged,” Head falconer Rufus Samkin told the BBC.

“We may see her again — we hope not. Hopefully, she’s learnt to keep her weight in trim so she can escape any predators or being picked up.”

Your belly fat is increasing the risk of a heart attack

For some time, researchers have identified abdominal obesity as an important risk factor for having a heart attack.

Now, new findings suggest that heart attack survivors who carry excessive belly fat around their waist are at an increased risk for a second or third heart attack. The risk for a subsequent stroke or heart attack was significant despite medication that is supposed to control cardiovascular health.

Credit: Pixabay.

Extra pounds and strokes go hand in hand. But belly fat, in particular, was much less studied.

Before the research team in Europe performed this study, the association between abdominal obesity and the risk of a subsequent heart attack or stroke was largely unknown.

“Patients are typically put on a stringent medical treatment regimen after their first attack to prevent second events (called secondary prevention),” said study author Dr. Hanieh Mohammadi of the Karolinska Institute, Stockholm, Sweden. “Secondary prevention works through reducing risk factors associated with heart attack and stroke such as high blood sugar, lipids and blood pressure. It was previously unknown whether abdominal obesity is a risk factor for recurrent events among patients on secondary prevention treatments.”

The study involved more than 22,000 patients, part of the SWEDEHEART registry, whose medical condition was followed after their first heart attack for a median of 3.8 years.

In this cohort, 78% of men and 90% of women had abdominal obesity, defined as a waist circumference of 94cm or more for men and 80cm or above for women.

Remarkably, the results suggest that abdominal obesity was associated with fatal and non-fatal heart attacks and strokes, regardless of other risk factors such as smoking, diabetes, hypertension, blood pressure, and body mass index, but also independent of any secondary prevention treatment. In other words, belly fat is an individual risk factor, no necessarily connected to being overweight.

What’s more, waist circumference was found to be a more important predictor of subsequent heart attacks than overall obesity.

Abdominal obesity is closely linked with conditions that accelerate the clogging of arteries, but also conditions that caused increased blood pressure, high blood sugar, and insulin resistance.

“Our results, however, suggest that there may be other negative mechanisms associated with abdominal obesity that are independent of these risk factors and remain unrecognised,” Mohammadi added. “In our study, patients with increasing levels of abdominal obesity still had a raised risk for recurrent events despite being on therapies that lower traditional risk factors connected with abdominal obesity – such as anti-hypertensives, diabetes medication and lipid lowering drugs.”

The higher the waist circumference, the greater the risk of a subsequent heart attack — and this relationship was stronger and more linear in men. In women, this relationship plotted a U-shaped graph, meaning that mid-range waist circumference was the least risky.

“Some studies have suggested that abdominal obesity may be more directly associated with the evil visceral fat (fat that sits around your organs) in men compared to women. In women it is thought that a greater portion of the abdominal fat is constituted by subcutaneous fat which is relatively harmless,” Dr. Mohammadi said, explaining why results differ so much between the sexes.

The findings, which were published in the European Journal of Preventive Cardiology, highlight the dangers of abdominal fat, which all people should strive to reduce to the best of their ability. After their first stroke, many patients feel more confident about their health outcomes because they start taking medication. But this study shows that if they have significant abdominal fat, they are still subjected to considerable risk of heart attack and stroke regardless of how many drugs they take.

Eating a healthy diet and regularly exercising are the best ways to reach an optimal waist circumference.

One in two American adults could be obese by 2030 — and one in four severely obese

Almost half of all adult Americans will be obese, and around a quarter will be severely obese, by 2030, according to a new study.

Image via Pixabay.

The paper, led by researchers at the Harvard T.H. Chan School of Public Health, predicts that more than half of the adult population of 29 US states will be obese by 2030 and that, among adults, all states will have an obesity prevalence of over 35% by the same year. They further estimate that the current rates of adult obesity and severe adult obesity in the US are around 40% and 18%, respectively.

Too big to fall

“The high projected prevalence of severe obesity among low-income adults has substantial implications for future Medicaid costs,” said lead author Zachary Ward, programmer/analyst at Harvard Chan School’s Center for Health Decision Science and lead author of the study.

“In addition, the effect of weight stigma could have far-reaching implications for socioeconomic disparities as severe obesity becomes the most common BMI category among low-income adults in nearly every state.”

The prediction is quite troubling as obesity comes associated with several health and economic impacts, on both an individual and social scale. Severe obesity is especially linked to increased rates of chronic disease and medical spending, the team explains, and with drastic reductions in life expectancy.

The team drew on self-reported body mass index (BMI) data from adults who participated in the Behavioral Risk Factor Surveillance System Survey (BRFSS) between 1993 and 2016 (for a total of 6.2 million data points). The BMI is calculated by dividing a person’s weight in kilograms by the square of their height in meters. A BMI of over 30 is considered indicative of obesity, while one of 35 or higher corresponds to severe obesity.

Since self-reported data in general and self-reported BMIs, in particular, tend to be unreliable (as people conform to their own biases), the team developed and used novel statistical methods to correct the data. Furthermore, using the wealth of information collected by the BRFSS, they looked at obesity rates for specific states, income levels, and subpopulations.

Several US states will have adult obesity rates close to 60% by 2030, they report, while the least-affected states will still record rates close to 40%. On a national average, they report, severe obesity will become the most common BMI category for women, non-Hispanic black adults, and those with annual incomes below $50,000 per year.

The team hopes that their study will help guide policy meant to prevent such a situation. For example, they cite previous research showing that a tax on sugar-sweetened beverages is an efficient and cost-effective prevention method for obesity.

“Prevention is going to be key to better managing this epidemic,” said Ward.

The paper “Projected U.S. State-Level Prevalence of Adult Obesity and Severe Obesity” has been published in the New England Journal of Medicine.

Obesity and undernutrition now come together — over 1 in 3 poor and middle-income countries struggle with both

Many low- to middle-income countries struggle with issues of undernutrition. Around a third of them, however, are faced with a very unusual problem: undernutrition and obesity at the same time.

Obesity and undernutrition have become increasingly connected in recent decades, a new paper reports. It explains that modern food systems are negatively impacting the health of poorer countries around the world, with the poorest being particularly affected. The authors also look at the causes, context, and possible solutions to this issue.

The faults in our food

“We are facing a new nutrition reality where major food system changes have led the poorest countries to have high levels of overweight and obesity along with undernutrition,” says Barry M. Popkin, lead author of the paper and W.R. Kenan Jr. Distinguished Professor of Nutrition at the University of North Carolina.

“Our research shows that overweight and obesity levels of at least 20% among adults are found in all low-income countries. Furthermore, the double burden of high levels of both undernutrition and overweight occurs primarily in the lowest-income countries — a reality that is driven by the modern food system. This system has a global reach and is preventing low- and even moderate-income countries and households from consuming safe, affordable, and healthy diets in a sustainable way.”

Global estimates place the total number of obese children and adults in the world at some 2.3 billion, the paper explains. It’s just one half of the issue known as the double burden of malnutrition — the other being undernutrition, a deficiency of calories or (in this context) essential nutrients.

For the study, the team used survey data from low- and middle-income countries in the 1990s and 2010s to estimate which of them were experiencing the double burden of malnutrition. If over 15% of a country’s population had wasting and over 30% stunting, over 20% of its women show thinness, and over 20% of its citizens in total were overweight, the team considered that particular country to be experiencing this double burden.

Over a third of low- and middle-income countries satisfy this condition — 45 of 123 countries in the 1990s and 48 of 126 countries in the 2010s — meaning they’re experiencing both forms of malnutrition. It was most commonly seen in sub-Saharan Africa, East Asia and the Pacific, and South Asia where 29, 9, and 7 countries were affected, respectively. In the 2010s, 14 more countries (with some of the lowest incomes in the world) had started to experience this double burden of malnutrition compared to the 1990s.

In comparison, low- and middle-income countries that enjoy the highest incomes in the category were much less likely to experience this issue, the team adds. In their view, this is indicative of a growing number of overweight people in the poorest countries even as large segments of the population face stunting, wasting, and thinness.

“Emerging malnutrition issues are a stark indicator of the people who are not protected from the factors that drive poor diets,” Popkin says. “The poorest low- and middle-income countries are seeing a rapid transformation in the way people eat, drink, and move at work, home, in transport, and in leisure.”

“The new nutrition reality is driven by changes to the food system, which have increased the global availability of ultra-processed foods that are linked to weight gain while also adversely affecting infant and preschooler diets. These changes include disappearing fresh food markets, increasing numbers of supermarkets, and the control of the food chain by supermarkets and global food, catering, and agriculture companies in many countries.”

But how can someone be both underfed and overfed at the same time? It comes down to the quality of food they can access. Ultra-processed foods are a very attractive option for people with low incomes, as they’re convenient (they require very little time investment to prepare), they seem hearty and are widely available. However, while they usually pack a caloric punch, they’re very poor in nutrients; in essence, they’re empty calories. Even worse, they usually contain a high level of additives to make them more appealing and to increase shelf-life, which can have adverse effects on health and body mass.

In an ironic twist of fate, healthy options such as fresh vegetables can be effectively out of reach for people with low incomes who may not have the purchasing power or time necessary to acquire and prepare them, or simply haven’t been educated on the drawbacks of their current diet.

The authors recommend “double-duty” policies aimed at reducing both the risk of nutritional deficiency and that of obesity and its related effects. They call for a concentrated effort from local governments, civil society, academia, the private sector, and the United Nations to create the economic conditions needed to address the double burden of malnutrition to devise and implement such strategies.

We also shouldn’t make the error of believing this issue is limited solely to ‘someplace else’. Previous research has highlighted that over half of America’s calories come from ultra-processed foods, and that they are responsible for 90% of the total added sugar intake in the country.

The paper “Dynamics of the double burden of malnutrition and the changing nutrition reality” has been published in the journal The Lancet.

Why we gain weight as we age

As we age, it becomes increasingly difficult to control our weight despite keeping caloric intake and exercise intensity constant. One important factor that may be responsible for this age-related effect may be lipid turnover, which decreases in older people, a new study found.

Credit: Pixabay.

The study performed by a team at the Karolinska Institutet in Sweden studied the fat cells of 54 men and women over a period of 13 years. During this time, all participants showed decreases in lipid turnover in the fat tissue — the rate at which lipids (i.e. fat) is removed and stored.

Adipose tissue mass (body fat) is determined by the storage and removal of triglycerides in adipocytes, also known as fat cells. The new study found that the participants who didn’t compensate for their lower lipid turnover rate by eating fewer calories or exercising more gained 20% more weight on average.

There is still very little we know about how triglyceride storage and removal in adipocytes works, but what has become increasingly clear is that this balance is critical to body fat mass. Previously, studies suggested that one way to speed up lipid turnover in fat tissue is to exercise more, and the new research seems to support this notion.

“Obesity and obesity-related diseases have become a global problem,” says Kirsty Spalding, senior researcher in the Department of Cell and Molecular Biology at Karolinska Institutet and another of the study’s main authors. “Understanding lipid dynamics and what regulates the size of the fat mass in humans has never been more relevant.”

A 2011 study found that triglyceride removal rate from fat tissue is decreased and the amount of triglycerides stored each year is increased in individuals suffering from obesity. In other words, it becomes increasingly easy to gain weight once you pass a certain threshold. Weight gain begets more weight gain, in a vicious cycle that becomes increasingly difficult to break.

The Swedish researchers also looked at lipid turnover in 41 obese women who underwent bariatric surgery. The women’s weight gain was analyzed over a period of four to seven years post-surgery. The results suggest that those who had a lower lipid turnover rate before surgery managed to actually increase their lipid turnover and maintain their weight loss.

“The results indicate for the first time that processes in our fat tissue regulate changes in body weight during ageing in a way that is independent of other factors,” says Peter Arner, a professor at the Department of Medicine in Huddinge at Karolinska Institutet and one of the study’s main authors. “This could open up new ways to treat obesity.”

The findings appeared in Nature Medicine.

Obese people enjoy their food more — and this could be key to understanding obesity

The satisfaction obtained from eating can help to explain the propensity to overeat, according to a new study, which revealed that people with obesity have stronger and longer-lasting taste perceptions than people with normal weight.

Credit: Kevin Krejci (Flickr)


The study, published in the Journal of the Academy of Nutrition and Dietetics, analyzed the satisfaction obtained from eating food. While there was no significant difference between individuals with normal weight and overweight, there was a difference with obese people. Simply put, obese people seem to enjoy their food more.

“If people with obesity have different taste perceptions than nonobese people, it could lead to a better understanding of obesity and possibly designing new approaches to prevent obesity,” explained lead investigator Linnea A. Polgreen from the University of Iowa.

The more you eat something, the more you derive less pleasure from it — which leads to a decline in taste perception. The relationship between perceived taste and quantity consumed has traditionally been referred to as sensory-specific satiety.

Researchers at the University of Iowa carried out a trial with 290 adults to measure their taste perceptions and understand how they differed among those with normal weight, those with overweight and those with obesity.

All participants were offered one piece of chocolate at a time and they could eat as much as they wanted without feeling uncomfortable. They consumed between two and 51 pieces. Half of the study participants received nutritional information about the chocolate before the test began.

Researchers found that individuals with obesity had higher levels of initial taste perception and rated subsequent pieces higher than their counterparts without obesity. Their ratings also declined at a more gradual rate compared to participants with normal weight and those with obesity.

At the same time, they discovered that people hungrier prior to the study had greater taste perception and that women’s taste perceptions declined faster than men. Providing nutritional information prior to chocolate consumption did not affect taste perception.

“People with obesity reported a higher level of satisfaction for each additional piece of chocolate compared to nonobese people. Thus, their taste preferences appear markedly different,” said Aaron Miller, co-investigator. “Obese participants needed to consume a greater quantity of chocolate than nonobese participants to experience a similar decline in taste perceptions.”

The findings from the research could help think about new strategies to deal with obesity, a significant public health problem that affects 30% of the US population. Understanding and manipulating taste perceptions, in addition to targeting nutritional awareness, may be crucial to understanding and preventing obesity. one of the most challenging issues of our times.

Ultra-processed foods cause weight gain, over eating, according to a new study

A preliminary study reports that eating ultra-processed leads to eating more calories and weight gain.

Instant Noodles.

Image via Pixabay.

People who eat ultra-processed foods have a higher calorie intake and gain more weight compared to those who eat a minimally-processed diet, a new study from the National Institutes of Health reports. This difference, the team explains, was seen even when participants in the ultra-processed and minimally-processed diet groups received the same number of calories and macronutrients in their food.


“Though we examined a small group, results from this tightly controlled experiment showed a clear and consistent difference between the two diets,” said Kevin D. Hall, Ph.D., an NIDDK senior investigator and the study’s lead author.

“This is the first study to demonstrate causality — that ultra-processed foods cause people to eat too many calories and gain weight.”

The study, at the NIH’s National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), was small-scale — it only included 20 adult volunteers. The authors report that it is the first randomized trial meant to look into the effects of ultra-processed foods as defined by the NOVA classification system. Previous observational studies, they explain, worked with large groups of people and have uncovered an association between diets with high amounts of processed food and health complications. However, these efforts had been randomized, so they can’t be used to establish a clear link between the two (people might have experienced health complications due to other factors, such as lack of access to fresh food, not necessarily from ultra-processed ones).

Under the NOVA system, foods that have ingredients predominantly found in industrial food manufacturing, such as hydrogenated oils, high-fructose corn syrup, flavoring agents, and emulsifiers, are considered to be “ultra-processed”.

“Results from this tightly controlled experiment showed a clear and consistent difference between the two diets,” said Kevin D. Hall, Ph.D., an NIDDK senior investigator and the study’s lead author. “This is the first study to demonstrate causality — that ultra-processed foods cause people to eat too many calories and gain weight.”

The participants, 10 male and 10 female, were admitted to the NIH Clinical Center for one continuous month. They were placed on each diet for two weeks (in random order), the team providing them with meals consisting of either ultra-processed or minimally processed foods. An ultra-processed breakfast, for example, might consist of a bagel, cream cheese, and turkey bacon, while the unprocessed breakfast was oatmeal with bananas, walnuts, and skim milk. Meals in both courses were controlled to have the same amounts of calories, sugars, fiber, fat, and carbohydrates. Participants were allowed to eat as much as they wanted.

People on the ultra-processed diet ate about 500 calories more per day than those on the unprocessed one. They also ate faster and gained weight, whereas their counterparts lost weight. On average, participants in the ultra-processed group gained 2 pounds (0.9 kilograms) and lost an equivalent amount on the unprocessed diet. “We need to figure out what specific aspect of the ultra-processed foods affected people’s eating behavior and led them to gain weight,” Hall admits. For example, the team says that slight differences in protein levels between the ultra-processed and unprocessed diets used in the study could explain up to half of the difference in caloric intake between the two groups.

“The next step is to design similar studies with a reformulated ultra-processed diet to see if the changes can make the diet effect on calorie intake and body weight disappear,” Hall explains.

“Over time, extra calories add up, and that extra weight can lead to serious health conditions,” said NIDDK Director Griffin P. Rodgers, M.D. “Research like this is an important part of understanding the role of nutrition in health and may also help people identify foods that are both nutritious and accessible — helping people stay healthy for the long term.”

While the study reinforces the benefits of unprocessed foods, researchers note that ultra-processed foods can be difficult to restrict. “We have to be mindful that it takes more time and more money to prepare less-processed foods,” Hall said. “Just telling people to eat healthier may not be effective for some people without improved access to healthy foods.”

The paper “Ultra-Processed Diets Cause Excess Calorie Intake and Weight Gain: An Inpatient Randomized Controlled Trial of Ad Libitum Food Intake” has been published in the journal Cell Metabolism.

Credit: Pixabay.

Obesity is rising faster in rural areas than in cities

Credit: Pixabay.

Credit: Pixabay.

The rise of obesity around the world has coincided with rapid urbanization. Naturally, this led to the assumption that the city lifestyle may be to blame for the uptick in overweight and obese individuals. However, a huge study which examined more than a hundred million people suggests that most of the rise in obesity is attributed to people living in rural areas rather than people living in cities.

The modern rural lifestyle is no longer healthy

Majid Ezzati, a public health expert at the Imperial College London in the United Kingdom, and colleagues conducted a massive meta-analysis of over 2,000 studies involving 112 million adults from rural and urban areas across the world from 1985 to 2017. The researchers correlated the study participants’ body mass index (BMI) — a measure of body fat based on height and weight — with their locations.

The authors’ analysis showed that contrary to popular belief, BMI has risen faster in rural areas than in urban ones, with the notable exception of sub-Saharan Africa. More than 55% of the rise in BMI in the world for both men and women comes from rural areas — and more than 80% in some low- and middle-income regions. Urban populations have only seen a global rise in BMI of 30%.

The most dramatic changes were experienced in developing countries such as Chile, Malaysia, and Turkey. For instance, in 1985, rural populations in these countries had a low BMI, but by 2017 obesity rates had become higher than those in urban centers, a trend which was especially prevalent in women.

There are a number of factors that can explain these findings. Rural areas in developing countries have gone through a lot of changes in the past three decades as their economies grew. Millions of people now have access to running water and energy to fuel the needs of their communities, including vehicles. However, this also means that people in rural areas are no longer forced to perform as much physical labor as they had to in the past, such as fetching freshwater or firewood.

In industrialized countries, such as the USA or the European Union, the heightened BMI trend can be explained by infrastructure, food access, and lifestyle choices. For instance, people living in rural areas have to use their cars more and have limited access to sports facilities compared to urban dwellers. It’s also easier to find fresh food in urban centers, and often at a lower cost, too, than in rural areas, according to the study published in the journal Nature

The BMI changes in sub-Saharan Africa represented an exception to the trend seen elsewhere in the world. Here, urban BMI rose faster than in rural populations. In countries such as Nigeria or the Democratic Republic of Congo, cities have expanded extremely rapidly while rural areas have remained poor (i.e. limited infrastructure and jobs). What’s more, in sub-Saharan Africa, wood is the most widely used fuel in rural areas whereas urban centers employ commercial fuels. This implies that more physical activity is being performed in rural areas in order to fetch resources. There is also a lack of access to running water in rural areas while food in urban centers is often of lower quality.

The study focused on growth rates rather than absolute numbers, but even so, in most rich countries, there are more obese people outside of cities than inside them. Hopefully, these findings will help guide better policies in order to stave off the growth of obesity.

“There is an urgent need for an integrated approach to rural nutrition that enhances financial and physical access to healthy foods, to avoid replacing the rural undernutrition disadvantage in poor countries with a more general malnutrition disadvantage that entails excessive consumption of low-quality calories,” the authors concluded.

Philadelphia’s sugary drink tax worked: one year later, consumption dropped by 38%

In January 2017, Philadelphia became the second city in the United States to implement a tax on the distribution of sugary and artificially sweetened beverages. Two years later, the tax is believed to have taken 83 million cans of soda off the streets — the equivalent of 28 million kgs of sugar (62 million pounds).

The world is facing an unprecedented health crisis: obesity. Worldwide obesity has nearly tripled since 1975, with more than 1.9 billion adults being overweight, and over 650 million being obese. Most of the world’s population live in countries where overweight and obesity kills more people than underweight, and although obesity is preventable through healthy nutrition and lifestyle, it shows no sign of slowing down.

Sugar is one of the main culprits in the current obesity crisis. There’s sugar in everything, from foods and sauces to sugary drinks, and the world just can’t seem to have enough of it. We’re eating too much sugar and it’s high time to stop this unless we want to deal with absolutely catastrophic consequences.

Sugary drinks are around 5-15% sugar, and contain essentially no nutrients. In other words, when you’re having this type of drink, you’re ingesting water and sugar, with no benefits. There is a mountain of science connecting sugary drink consumption to long-term health issues such as obesity and diabetes.

Health scientists and economists have long advocated for a sugary drink tax and, in 2017, Philadelphia took action.

“Taxing sugar-sweetened beverages is one of the most effective policy strategies to reduce the purchase of these unhealthy drinks. It is a public health no-brainer and a policy win-win,” said first author Christina A. Roberto, PhD, an assistant professor of Medical Ethics & Health Policy in the Perelman School of Medicine at the University of Pennsylvania. “It’s likely to improve the long-term health of Philadelphians, while generating revenue for education programs in the city of Philadelphia.”

The city implemented a 1.5-cents-per-ounce tax (50 cents per liter). The rationale behind the tax was twofold: on one hand, the tax would raise money which would be used for educational and health projects and, on the other hand, the consumption of sugary drinks would drop.

It worked.

According to Penn Medicine researchers, the consumption of sugary and artificially sweetened beverages dropped by 38% in chain food retailers, one year after the tax was introduced. This was projected to happen, but now there is official confirmation. Overall, between January 2016 and December 2017, there was a 59% reduction in taxed beverage sales at supermarkets, a 40% reduction at mass merchandisers, and a 13%reduction at pharmacies. This wasn’t caused by any external factor —  when researchers looked at sales just outside of Pennsylvania (where the tax was not applied), they found that sales actually increased. In a separate study, researchers also report that unemployment was not affected by the beverage tax, something which the sugary drinks industry claimed would happen.

“Philadelphia’s tax on sweetened drinks led to a huge reduction in sales of these unhealthy drinks one year after it was implemented and generated revenue for thousands of pre-k slots. That’s great news for the well-being of the people of Philly,” Roberto said.

Philadelphia isn’t alone in this endeavor. Several cities in the US (including San Francisco and Boulder) have implemented similar taxes, with similar positive results. However, at the national level, there is still no talk of such a tax in the US. Meanwhile, countries such as Mexico and the UK have implemented a sugar tax and have also reported reduced consumption after the tax.

Although there are some concerns regarding such a tax and there may be significant geographical variations, the overwhelming scientific consensus seems to be that taxing sugary drinks has a positive impact.

Results were published this week in JAMA,

Credit: Pixabay.

Bad diet kills 1 in 5 people worldwide — it’s even worse than smoking

Credit: Pixabay.

Credit: Pixabay.

Having a poor diet is worse than lack of exercise, sleep deprivation, and even smoking. According to a huge study that involved more than 130 scientists across 40 countries, poor diets were responsible for 22% of all adult deaths in 2017.

“This study affirms what many have thought for several years – that poor diet is responsible for more deaths than any other risk factor in the world,” said lead study author Dr. Christopher Murray, Director of the Institute for Health Metrics and Evaluation.

Poor diet is an “equal opportunity killer”, researchers say

Diets high in sodium (too much salt) were associated with the most diet-related deaths, followed by whole grain deficiency and not consuming enough fruit, vegetables, fiber, nuts, and omega-3 from seafood. Poor diets led to 10.9 million deaths in 2017, with cardiovascular disease ranking as the primary cause, followed by cancer and diabetes.

Out of all 195 countries, the highest proportion of diet-related deaths was recorded in Uzbekistan (892 diet-related deaths per 100,000 people), and the lowest was measured in Israel (89 diet-related deaths per 100,000 people). The United States ranked 43rd on the list.

Perhaps unsurprisingly, countries which follow the Mediterranean diet — which emphasizes eating fresh, whole foods — ranked among the lowest in terms of diet-related deaths. For instance, Israel, Spain, and France had good scores for healthy diets.

The mortality rate per 100,000 people attributable to diet in 2017. Credit: The Lancet.

The mortality rate per 100,000 people attributable to diet in 2017. Credit: The Lancet.

After they analyzed 15 dietary factors, the researchers found that most diet-related deaths were generally associated with not eating enough healthy foods (whole grains, fruit, nuts, and seeds) rather than eating too many unhealthy foods (trans fats, sugary drinks, and high levels of red and processed meats).

“While sodium, sugar, and fat have been the focus of policy debates over the past two decades, our assessment suggests the leading dietary risk factors are high intake of sodium, or low intake of healthy foods, such as whole grains, fruit, nuts and seeds, and vegetables. The paper also highlights the need for comprehensive interventions to promote the production, distribution, and consumption of healthy foods across all nations,” Murray said.

Poor diets do not kill overnight but rather slowly cause a person’s bodily functions to collapse. The same study found that poor dieting was responsible for 255 million disability-adjusted life years (DALYs) — the number of years spent living with disabilities as a consequence of poor diets across the studied populations. Overall, a poor diet is responsible for 16% of adult DALYs worldwide.

The authors recommend that people switch to a more balanced diet which is rich in fruits and veggies, nuts and seeds, plant-based protein, and whole grains, while decreasing the consumption of sugary drinks, processed foods, red meat, and foods high in sodium.

The findings were reported in The Lancet.

“Vested interests” cause major threat to human existence, researchers say

The global triangle of obesity, undernutrition, and climate change represents ‘The Global Syndemic’ — the greatest threat to human and planetary health, researchers say. The underlying causes of this syndemic are commercial vested interests, lack of political leadership, and insufficient societal demand for change.

Image in public domain.

A Global Syndemic

“Syndemic” is not a word you hear very often — and you most definitely don’t want to hear. It represents an aggregation of two or more epidemics or diseases which exacerbate the total damage. The ‘Global Syndemic’ refers to the devastating combination of obesity, undernutrition, and climate change — which a new report published in the Lancet identifies as the single largest threat to mankind and Earth.

Excess body weight is estimated to affect 2 billion people worldwide, causing 4 million deaths every year. At the same time, stunting and wasting affect 155 million and 52 million children worldwide, respectively; 2 billion people suffer from a micronutrient deficiency, and 815 million people are chronically undernourished. Malnutrition is the single biggest cause of ill-health globally. Climate change is already affecting the lives of most people on Earth, with devastating consequences. Even from a purely economic standpoint, these issues account for an excess of 20% of the global GDP — but from a humanitarian perspective, it’s an unmitigated disaster.

The first thing we must change, the Lancet Commission on Obesity argues, is our perspective. These three issues are generally regarded as separate — but they share a common backbone: a global policy focusing on economic growth, ignoring negative health effects, environmental damage, and social inequality.

“Until now, undernutrition and obesity have been seen as polar opposites of either too few or too many calories. In reality, they are both driven by the same unhealthy, inequitable food systems, underpinned by the same political economy that is single-focused on economic growth, and ignores the negative health and equity outcomes. Climate change has the same story of profits and power ignoring the environmental damage caused by current food systems, transportation, urban design and land use. Joining the three pandemics together as The Global Syndemic allows us to consider common drivers and shared solutions, with the aim of breaking decades of policy inertia,” says Commission co-chair, Professor Boyd Swinburn of the University of Auckland.

The effects of these issues are also intertwined. For instance, climate change will disproportionately affect the underdeveloped parts of the world, bringing even more food insecurity and extreme weather events. Fetal and infant malnutrition has also been shown to increase the risk of adult obesity, and climate change also increases the price of numerous food commodities, especially fruits and vegetables, which can fight global obesity. Overall, things revolve in a connected triangle, making each other worse, just like several diseases can make each other worse by collapsing the immune system.

The solutions, therefore, must also act on all these issues in conjunction.

“We must recognise these connections and implement double-duty actions that address both obesity and undernutrition and triple-duty actions that influence multiple parts of the syndemic simultaneously,” says Commissioner Professor Corinna Hawkes, City University London (UK).

It sounds weird to say that measures against obesity would also fight climate change (and vice versa), but here’s a very simple example: what if we were to tax red meat? Red meat requires a disproportionate amount of resources, produces a huge amount of greenhouse gases, and at the same time, it is a major contributor to the global obesity crisis. The tax money could be used to alleviate world hunger or promote healthier and more sustainable alternatives. Supporting active transportation in the form of walking, cycling, or using public transportation is another excellent example: this could reduce some of the greenhouse gases coming from transportation, while at the same time making people more healthier and alleviating infrastructure strain as a bonus.

So why aren’t we doing more of this?

Vested interests

The reason, the report explains, is shockingly straightforward: powerful vested interests oppose it. It’s very rare to see a scientific report being so trenchant about something so delicate, and that’s exactly what makes it so important to heed its warning.

Image in public domain.

Economic power has been increasingly concentrated into fewer, larger companies. These companies are investing heavily in lobbying to promote their own policies and reject any health-based policy that would attack their profits.

It’s well known that major fossil fuel companies have denied climate change for decades, even though they knew it was happening as a direct result of their activities. At the same time, subsidies from the US government keep the price of oil artificially low — subsidies which would be better diverted towards more sustainable forms of energy. Attempts to include sustainability in national dietary guidelines in the USA and Australia failed as a result of corporate lobbying from the food industry, which pushed to remove sustainability from the terms of reference. Lobby from the sugary drinks industry has also been very successful against local initiatives to reduce soda consumption, and it research funded by this industry is five times less likely to find an association between sugary drinks and obesity compared to other studies.

All in all, it seems that this financial and market power of the world’s major companies translates into political power, preventing regulation that would be beneficial for people.

“With market power comes political power, and even willing governments struggle to get policies implemented against industry pressure. New governance dynamics are needed to break the policy inertia preventing action. Governments need to regain the power to act in the interests of people and the planet and global treaties help to achieve this. Vested commercial interests need to be excluded from the policy table, and civil society needs to have a stronger voice in policy-making. Without disruptive change like these, we will continue on with the status quo which is driving The Global Syndemic,” says Commissioner Tim Lobstein, World Obesity Federation

What should be done

Researchers are calling for a new worldwide social movement — which again, is highly unusual for a scientific report. Lobstein and colleagues say we need to radically rethink the relationship between the important players: policymakers, business, governance, and civil society. Since the business is the main driver of this situation and the governance and policymaking side also seem content with this status quo, it seems like the only potential source of change is the civil society. Effectively, all possible strategies that would fight this syndemic require larger support from all of us.

Not only do we need to make better individual decisions when it comes to our own lifestyles, but we need to push policymakers in the right direction and encourage them to make more sustainable decisions. Supporting businesses which take steps in the right direction is also important, as is not supporting the ones that don’t.

This type of social mobilization can work. We’ve seen the intention of the US administration to withdraw from the Paris Agreement, which itself is seen by many as not ambitious enough — so political deals can be surprisingly fragile. But even in this situation, 2,700 leaders from US cities, states, and businesses representing 159 million people and US$ 6.2 trillion in GDP have developed an alliance and continued to mitigate the effects of climate change. In Mexico and the UK, mobilization against sugary drinks has led to the implementation of a tax, despite strong resistance from the industry.

The businesses don’t need to be on the losing side of it, either. Of course, things like sugar, which have a clear negative effect (called a negative externality), should be taxed — but the only unfair thing is that this hasn’t happened so far. Similarly, the world’s leading economists are advocating for a carbon tax. But this all opens up new avenues for sustainable business models, the likes of which can turn a profit while not doing environmental and health damage. Furthermore, the incentive is to make the switch as early as possible but again, the drive needs to also come from the social level — from each and every one of us.

“The past few years have seen renewed activism at the local level, whether in cities, communities, or in particular issues. As with other social movements, such as campaigns to introduce sugary drink taxes, efforts to address the Global Syndemic are more likely to begin at the community, city, or state level, and subsequently build to a national or global level. Support for civil society is crucial to break the policy deadlock and the systems driving the Global Syndemic,” concludes Professor Dietz.

Credit: Pixabay.

Unhealthy weight responsible for 1 in 4 cases of asthma in obese children

Nearly 10% of all pediatric cases of asthma could be avoided if childhood obesity were eliminated, according to researchers at Nemours Children’s Health System. In raw numbers, almost one million children in the U.S. might have avoided the illness by maintaining a healthy weight.

Credit: Pixabay.

Credit: Pixabay.

Asthma is a respiratory condition marked by attacks of spasm in the bronchi of the lungs, causing difficulty in breathing. It is usually connected to an allergic reaction or other forms of hypersensitivity. Usually, the condition is caused by genetics and viral infections during childhood, which cannot be prevented. However, “obesity may be the only risk factor for childhood asthma that could be preventable,” said Jason Lang, Associate Professor of Pediatrics at Duke University and the study’s lead author.

For their retrospective study, Land and colleagues analyzed data for 507,496 children aged 2 to 17 gathered from more than 19 million doctor’s visits at six major children’s health centers. Those that were classified as having asthma had been diagnosed at two or more doctor’s appointments and had also received a prescription, such as an inhaler.

According to the findings, obese children had a 30% higher risk of developing asthma than their peers of a healthy weight. Meanwhile, children who were overweight but not obese also had a 17% increased asthma risk. The researchers calculated that 23% to 27% of new asthma cases in children with obesity are directly attributable to obesity. Researchers calculated the risk of asthma in children using several models and adjusted for factors such as sex, age, socioeconomic status, and allergies.

“Pediatric asthma is among the most prevalent childhood conditions and comes at a high cost to patients, families and the greater health system. There are few preventable risk factors to reduce the incidence of asthma, but our data show that reducing the onset of childhood obesity could significantly lower the public health burden of asthma,” said Terri Finkel, Chief Scientific Officer at Nemours Children’s Hospital in Orlando and co-author of the new study. “Addressing childhood obesity should be a priority to help improve the quality of life of children and help reduce pediatric asthma.”

Credit: Samiha Khanna/ Duke Health.

Credit: Samiha Khanna/ Duke Health.

The study suggests that 1 million cases of pediatric asthma, out of 6 to 8 million cases reported in the United States, can be attributed to being overweight and obesity. The researchers write that at least 10% of all US cases of asthma in children might be avoided in the absence of childhood overweight and obesity.

It’s not clear how obesity adds to the risk of developing asthma. Some hypotheses include potential differences in how children’s lungs and airways develop when they are overweight and inflammatory effects in the body due to obesity.

“I think it’s reasonable to be concerned that it’s a causal relationship,” Lang said. “It appears becoming overweight or obese as a child significantly increases your risk of developing asthma, and it’s a significant increase, directing attention again to the importance of preventing obesity at an early age.”

The findings appeared in the journal Pediatrics. 

It’s high time we moved past BMI — meet the metabolome

In today’s world, more than 2 billion people are overweight or obese — but the most commonly used test for obesity has some significant shortcomings.

A visual representation of the BMI.

To say that obesity is a big problem would be a severe understatement. Recent figures are alarming, especially in the US, where approximately every 1 in 3 adults is obese, which brings major health risks. However, obesity can be a surprisingly hard thing to define.

We all have a general idea of what it means (being severely overweight), but where do you draw the line exactly? The most used metric is the so-called BMI — the Body Mass Index.

BMI is a simple measure that uses weight and height. Essentially, it’s your body mass divided by the square of the body height and is universally expressed in the metric system (sorry) in kg/m2. There are countless BMI calculators you can use to find out your index, and it works like this: if your BMI is over 30, you’re obese. But there are many factors the simple BMI fails to consider.

For instance, muscle weighs much more than fat over a similar volume, so for a muscular and even slightly overweight person, BMI could rank them as obese — which is just not true. Conversely, your BMI might be lower due to a lack of muscle, which is not something ideal. So researchers want to come up with a better way to measure obesity.

In a new study, a team of researchers looked at people’s genomes and metabolomes (sets of small-molecule chemicals found within a cell) to see how they relate to the BMI, and how they can offer better information.

“We are attempting to identify the heterogeneity in what we currently call obesity. There’s a need for more precise ways of measuring,” says senior author Amalio Telenti (@atelentia), a genomics professor at Scripps Research. “Although it’s clear that obesity is linked to certain diseases, not everybody who is obese will have these consequences. Also surprising, you may not look obese but still have the problems of someone who is.”

The metabolome is essentially the sum of all the small-molecule chemicals found in a biological sample, including fatty acids, amino acids, sugars, and vitamins, to name a few. The metabolome reacts and changes whenever there are environmental or genetic changes and, in a way, it can be seen as an expression of the BMI.

“For most people, we found the metabolome is tied very closely to weight and BMI,” Telenti explains. “Every time someone gains or loses a pound, their metabolome changes. It’s almost linear.” But at the same time, he adds, “correlating well is not the same as correlating perfectly, and that’s where this work became very interesting.”

If the metabolome would simply express the BMI, then we wouldn’t have anything new, as we’ve already established that BMI has some important shortcomings. Instead, the metabolome shows some differences, particularly in people where the BMI could fail.

So what researchers have is basically a new way to define who’s metabolically healthy and who’s obese.

“There have been studies before of individuals whose BMI doesn’t match their metabolic health, but this is a new way of defining who is metabolically healthy,” says first author Liz Cirulli (@ETCirulli), a research scientist at Human Longevity Inc. “All across the weight spectrum, we found people who were heavier or lighter than expected based on their metabolome.” These differences were also found in a range of metabolites linked to various diseases.

The idea of studying human metabolome is not new — the Human Metabolome Database is a freely available, open-access database containing detailed data on more than 40,000 metabolites that have already been identified or are likely to be found in the human body. However, using it as a substitute for BMI is an intriguing idea, which could one day enable scientists to develop better obesity diagnoses.

However, this is still in the early phases, and much more research is needed before they can be validated and established for clinical use. Cirulli calls for more research, particularly on metabolic signatures for other traits, including blood pressure and measures of body fat. It will definitely take a while, but we may eventually have a comprehensive analysis of all the metabolites in their body with a simple blood test.

Journal Reference: Cell Metabolism, Cirulli et al. “Profound perturbation of the metabolome in obesity associates with health risk.” http://www.cell.com/cell-metabolism/fulltext/S1550-4131(18)30630-2

Losing sleep can lead to more extra pounds

Want to shed a few extra pounds? Here’s an idea, and it’s simple enough: try sleeping a bit more.

The link between sleep and obesity is not new — it’s been reported several times by researchers. A 2012 study found that lack of sleep can impact appetite regulation and impair glucose metabolism, while a 2011 review of studies found substantial evidence linking obesity and a lack of sleep. However, the exact nature of this link has not been thoroughly explained. A new study presents some of the most compelling evidence to date, showing that a lack of sleep encourages the body to store more fat, altering the body’s metabolism and an essential DNA function.

“Chronic sleep loss, social jet lag, and shift work—widespread in our modern 24/7 societies—are associated with an increased risk of numerous metabolic pathologies, including obesity, metabolic syndrome, and type 2 diabetes,” researchers explain in the new study. “Even minor weekly shifts in sleep timing, or as few as five consecutive nights of short sleep, have been associated with an increased risk of weight gain in healthy humans.”

Jonathan Cedernaes, a circadian researcher at Uppsala University in Sweden and lead author of the study says that sleep has an “irreplaceable” function, it’s not just to conserve energy and replenish our stamina. Yet many people tend to consider it an expendable resource — and this can have massive consequences.

Cedernaes and colleagues recruited 15 volunteers, who attended two testing sessions: once after a normal night’s sleep, and once after staying up all night. Biopsies and samples of fat, muscle tissue, and blood were also taken, and participants underwent a separate electroencephalography (EEG) and were asked to also complete sleep, food, and activity diaries as part of their screening.

The most significant change researchers note is in a gene activity called DNA methylation. The change was linked to cells increasing their tendency to absorb lipids, boosting the body’s ability to store fats. Furthermore, the participants’ muscle cells contained lower levels of structural proteins after a lack of sleep, suggesting a reduced ability to build and maintain muscles.

Lastly, scientists also report an increase in inflammation in the body after sleep deprivation, a major risk factor for type 2 diabetes, among others.

While previous studies have suggested a connection between obesity and sleep deprivation, this link was hard to separate from other lifestyle changes. Now, researchers have shown a physical mechanism that is responsible (or at the very least partially responsible) for this connection.

It should be said that the study featured a very small sample size and only analyzed a brief moment in the life of the participants. For the future, researchers call for more investigations to see what the effects of sustained sleep deprivation are on a wider segment of the population. But for now, it’s safe to say that sleep is not something you should be missing out on.

The study has been published in Science Magazine.

Obesity May Also Increase Flu Spread, Not Just Flu Severity

Credit: Pixabay.

Obesity and overweight

Overweight and obesity are conditions where a person has accumulated an excessive amount of fat that may impair their health. A simple index used to classify overweight and obesity is the body mass index (BMI), which is defined as a person’s weight in kilograms divided by the square of his height in meters (kg/m2). To learn more about obesity, BMI and how it is measured, check this information page from the World Obesity Foundation and the video below.

Obesity and diseases

A high BMI is a major risk factor for non-communicable diseases such as cardiovascular diseases (mainly heart disease and stroke), diabetes, musculoskeletal disorders (especially osteoarthritis – a highly disabling degenerative disease of the joints), and some cancers (including endometrial, breast, ovarian, prostate, liver, gallbladder, kidney, and colon). The risk of these non-communicable diseases rises with increases in BMI.

Obesity and infections

Available data suggest that obese people are more likely than people of normal weight to develop infections of various types including postoperative infections (infections after surgical procedures) and other nosocomial infections (infections that are acquired in a hospital or other healthcare facility). Scientists already know that obesity increases a person’s risk of suffering from severe complications from influenza. Previous epidemiologic studies in Morbidity and Mortality Weekly Report and PLoS Medicine showed an association between obesity and severe complications and death from influenza, especially in the elderly. However, recently researchers who studied households in Managua, Nicaragua over three flu seasons found that it takes obese adults about 1.5 times longer to shed the virus than non-obese adults. This was published in the Journal of Infectious Diseases (JID).

Obesity and flu transmission

Dr. Aubree Gordon from University of Michigan School of Public Health, a senior study co-author, said in a press release from the Infectious Diseases Society of America (IDSA) that the findings are the first real evidence that obesity might affect more than just disease severity; “it might directly impact transmission as well.”

Flu vs cold

Credit: Pixabay / Sambeet.

The researchers monitored two groups including 1,783 people from 320 households during three flu seasons from 2015 to 2017. Among the group, 87 were infected with influenza A while 58 were sickened by influenza B. It took obese adults with two or more symptoms 42% longer to shed the influenza virus compared to adults who were not obese. Moreover, obese adults who had no symptoms or had milder infections shed the virus for 104% longer. However, obesity did not increase viral shedding in children ages 5 to 17 or for adults who had influenza B illness.

The researchers cannot say for sure how obesity could extend viral shedding in those with flu; however, it is a known fact that obesity alters the immune system and can lead to chronic inflammation, which also increases with age. The researchers also note that obesity can make breathing more difficult and increase the need for oxygen. They also suggest that chronic inflammation triggered by obesity could be responsible for increased shedding of influenza A. Reducing obesity rates can have the benefit of limiting the spread of viral diseases, the authors said. Further research is needed to determine whether the flu virus shed over longer periods by obese patients is infectious and if it is able to infect others.

A commentary on the study was included in the same JID issue by Dr. Stacey Schultz-Cherry of St. Jude Children’s Research Hospital who was not involved in the study. Dr. Schultz-Cherry noted that more studies are needed to determine whether the longer shedding duration in obese people is correlated with increased viral load and shedding of infectious viral particles.

She added that this report of longer shedding of virus and a recent study of exhaled breath in college students — which found a link between obesity and the amount of flu virus shedding — suggest that obesity may play an important role in flu transmission. This link has important public health implications, including a threat of more flu transmission that goes along with increasing obesity prevalence. Dr. Schultz-Cherry noted that strategies to prevent flu could be a challenge because of poor vaccine response in overweight and obese populations.

Scientists warn of the risks of normalizing obesity

Normalization of obesity comes with some unwanted consequences

In a study which is bound to stir up a heated discussion, researchers have shown that the normalization of ‘plus’ body sizes may lead to people underestimating their weight, undermining efforts to reduce obesity.

Let’s get one thing out of the way: efforts to reduce body stigmatization and promote body positivity are welcome and much-needed in today’s society. However, the normalization of obesity is very dangerous, researchers warn.

The study by Dr. Raya Muttarak, from the University of East Anglia (UEA) and the International Institute for Applied Systems Analysis (IIASA), in Austria, analyzed data from 23,460 people who are overweight or obese, analyzing how they perceive their own weight; they found several interesting trends.

For instance, men are more likely than women to underestimate their weight, as are individuals with lower levels of education, both male, and female. As a result, these groups are significantly less likely to undergo weight-losing efforts. Members of minority ethnic groups are also more likely to underestimate their weight than the white population, however they are more likely to try to lose weight.

The results also show that the overall number of people who underestimate their weight has gone up: from 48.4% to 57.9% in men and 24.5% to 30.6% in women, between 1997 and 2015. As obesity rates are surging throughout much of the world, this is extremely important for devising health policies, Muttarak says.

“Seeing the huge potential of the fuller-sized fashion market, retailers may have contributed to the normalisation of being overweight and obese,” said Dr Muttarak. “While this type of body positive movement helps reduce stigmatisation of larger-sized bodies, it can potentially undermine the recognition of being overweight and its health consequences. The increase in weight misperception in England is alarming and possibly a result of this normalisation.

“Likewise, the higher prevalence of being overweight and obesity among individuals with lower levels of education and income may contribute to visual normalisation, that is, more regular visual exposure to people with excess weight than their counterparts with higher socioeconomic status have.

“To achieve effective public health intervention programmes, it is therefore vital to prioritise inequalities in overweight- and obesity-related risks. Identifying those prone to misperceiving their weight can help in designing obesity-prevention strategies targeting the specific needs of different groups.”

The causes of obesity are complex, Muttarak adds, and feature many socioeconomic determinants. The problem is further exacerbated by the fact that the prices of healthier foods such as fresh fruits and vegetables, are often higher than processed and energy-dense foods.

Obesity has been linked with a flurry of health problems including heart diseases, stroke, diabetes, breathing problems, and gout. Over 2 billion people worldwide are overweight or obese.

Normalization of Plus Size and the Danger of Unseen Overweight and Obesity in England’, Raya Muttarak, is published in Obesityvolume 26, number 7, July 2018.