Latest news with #HermanPontzer
Time of India
21-07-2025
- Health
- Time of India
What really causes obesity? Study says diet matters more than exercise
Obesity is a complex medical condition marked by excessive body fat that increases the risk of serious health problems such as heart disease, diabetes, high blood pressure, and certain cancers. While it's often believed that lack of exercise is the primary cause of obesity, a groundbreaking study published in PNAS challenges this assumption. Researchers found that people in both industrialised and developing societies burn a similar number of calories daily, regardless of how active they are. This suggests that physical inactivity may not be the main driver of the obesity epidemic. Instead, the study points to diet, particularly the overconsumption of ultra-processed foods as the leading cause. What is obesity, and its causes Obesity is a complex health condition characterized by excessive body fat. It's not merely a cosmetic issue, it's a serious medical concern that significantly raises the risk of various diseases. Obesity doesn't have a single cause. It usually results from a combination of factors, including: Genetics: Family history can predispose individuals to obesity. Hormonal and metabolic factors: Hormonal imbalances and slowed metabolism play a role. Lifestyle habits: High-calorie diets, especially rich in ultra-processed foods, are a major contributor. Physical inactivity: Although not the sole cause, sedentary lifestyles can worsen weight gain. Environmental factors: Limited access to healthy foods, poor sleep, and stress can also contribute. Medications: Certain drugs (e.g., antidepressants, corticosteroids) can lead to weight gain. 'Constrained Total Energy Expenditure' model of the study Researchers measured total energy expenditure among over 4,200 individuals across 34 countries with lifestyles ranging from hunter-gatherers to city dwellers using the gold standard 'doubly labeled water' method. Surprisingly, when adjusted for body size, daily calorie burn was almost identical regardless of lifestyle, debunking the idea that less activity equals fewer calories burned This finding supports the constrained total energy expenditure model, which suggests our bodies regulate energy use within a fixed range, even with increased activity. by Taboola by Taboola Sponsored Links Sponsored Links Promoted Links Promoted Links You May Like Many Irish Citizens Don't Know About This Read More Undo According to lead author Herman Pontzer, overeating, especially ultra-processed foods, is nearly ten times more responsible for obesity than decreased calorie burn. Is exercising still important to manage obesity? The study does not suggest abandoning exercise. While exercise may not significantly influence weight loss on its own, it plays a crucial role in: Maintaining weight after loss Improving cardiovascular and metabolic health Enhancing mood and mental clarity Building muscle and bone strength Increasing lifespan Exercise is essential for overall well-being, but controlling calorie intake is more effective for managing obesity. Health complications of obesity Unchecked obesity can lead to life-threatening complications, including: Insulin resistance and type 2 diabetes Heart attacks and strokes Liver damage and gallbladder disease Reproductive issues and infertility Increased risk of surgical and anesthetic complications Poor mental health: depression, anxiety, low self-esteem Certain types of cancer (Breast, Colon) Also read | What causes bloating: Discover the foods and tips that help reduce bloating
Time of India
17-07-2025
- Health
- Time of India
Lack of exercise or a high-calorie diet -- What causes obesity? Major new study offers surprising insight
Couch potatoes have always had bad press. But turns out, the over-the-top foodies are equally guilty – if not more. Obesity, now a global public health crisis, has long been blamed on sedentary lifestyles and high‑calorie diets. In 2025, global obesity rates are projected to continue rising, with estimates suggesting that one in five adults worldwide will have obesity. This trend indicates that countries are significantly off track to meet the World Health Organization's (WHO) 2025 targets to halt the rise of obesity. What's more? The World Obesity Federation's 2025 Atlas highlights that many countries lack sufficient policies and plans to address the escalating obesity crisis. Amidst that, a major new study published in Proceedings of the National Academy of Sciences sheds surprising light on the root causes. Is it the sedentary lifestyle alone? Or is the high-calorie diet to be blamed for it? Read on to know more. The study The new study, led by Dr. Herman Pontzer at Duke University, has flipped traditional ideas about the origins of obesity on their head, highlighting that our diets might hold more weight, literally and figuratively, than the amount of physical activity we engage in. by Taboola by Taboola Sponsored Links Sponsored Links Promoted Links Promoted Links You May Like Victoria Principal Is Almost 75, See Her Now Reportingly Undo Published this week in the Proceedings of the National Academy of Sciences (PNAS), the research challenges the long-held belief that individuals in developed countries like the United States of America lead relatively inactive lifestyles and consequently burn fewer calories. Surprisingly, it reveals that calorie-burning rates among people in developed nations are comparable to those of individuals in less industrialized regions, including farmers, herders, and hunter-gatherers who enjoy more active routines. More specifically – the researchers calculated total energy expenditures for 4,213 men and women from 34 countries or cultural groups, and found they were similar, regardless of whether someone was an American office worker or a hunter-gatherer. This groundbreaking research work, examining the energy expenditure and metabolic rates of those individuals from diverse nations, proposes that inactivity might not be a significant contributor to obesity in the US or beyond. Instead, the study emphasizes that dietary choices play a much larger role than the decrease in energy expenditure associated with economic progress. As per the study, what people eat 'plays a far greater role than reduced expenditure in the elevated prevalence of obesity associated with economic development.' The experts' take Herman Pontzer, a professor and senior author of the study, shared with the Washington Post that these findings are pivotal in helping health officials pinpoint the true causes of obesity, paving the way for more effective treatments. Alongside more than 80 co-authors, Pontzer collected data from laboratories worldwide utilizing doubly labeled water in metabolism studies, a method that precisely measures energy expenditure. Contrary to the notion that increasing exercise would lower obesity rates, the study reveals that 'increased energy intake has been roughly 10 times more important than declining total energy expenditure in driving the modern obesity crisis,' according to the authors. In simpler terms, populations grappling with higher obesity rates are consuming excessive amounts of food, often the wrong types, as Pontzer explained. Barry Popkin, a professor at the Gillings School of Global Public Health at the University of North Carolina at Chapel Hill and a recognized obesity expert, told the Post, 'This study confirms what I've been saying, which is that diet is the key culprit in our current [obesity] epidemic.' He added that 'this is a well-done study,' a sentiment echoed by other professionals in the field. Dariush Mozaffarian, director of the Food is Medicine Institute at Tufts University in Boston, stated, 'It's clear from this important new research and other studies that changes to our food, not our activity, are the dominant drivers of obesity.' What's ahead, then? As the study reveals, obesity's roots are multifaceted. The latest evidence confirms that while you can't outrun a bad diet, you can transform your health by choosing what and how much you eat. It is now a proven fact that proper diet plays a tad bit more important role in managing weight and keeping obesity in check than a laid-back lifestyle. Should we go back to our couches then, instead of picking up the dumbbells? That doesn't sound wise. This landmark study rather revolutionizes our understanding of obesity: metabolic adaptation buffers against exercise-driven calorie deficits, while poor diet remains the primary villain. To tackle the obesity epidemic, public health must realign – from 'move more' to 'eat smart.' Coupling smart eating habits with regular exercise provides the best defense. In fact, Pontzer stressed that these findings do not diminish the importance of exercise for our overall health. 'We know that exercise is essential for health. This study doesn't change that,' he affirmed. However, he advocated that to tackle obesity effectively, 'public health efforts need to focus on diet,' particularly concerning ultra-processed foods, as Pontzer highlighted. Exercise during pregnancy may save kids from health problems as adults, says study
Yahoo
15-07-2025
- Health
- Yahoo
What causes obesity? A major new study is upending common wisdom.
Obesity is uncommon among Hadza hunter-gatherers in Tanzania, Tsimane forager-farmers in Bolivia, Tuvan herder-farmers in Siberia, and other people in less-developed nations. But it's widespread among those of us in wealthy, highly industrialized nations. Why? A major study published this week in PNAS brings surprising clarity to that question. Using objective data about metabolic rates and energy expenditure among more than 4,000 men and women living in dozens of nations across a broad spectrum of socioeconomic conditions, the study quantified how many calories people from different cultures burn most days. Subscribe to The Post Most newsletter for the most important and interesting stories from The Washington Post. For decades, common wisdom and public health messaging have assumed that people in highly developed nations, like the United States, are relatively sedentary and burn far fewer daily calories than people in less-industrialized countries, greatly increasing the risk for obesity. But the new study says no. Instead, it finds that Americans, Europeans and people living in other developed nations expend about the same number of total calories most days as hunter-gatherers, herders, subsistence farmers, foragers and anyone else living in less-industrialized nations. That unexpected finding almost certainly means inactivity is not the main cause of obesity in the U.S. and elsewhere, said Herman Pontzer, a professor of evolutionary anthropology and global health at Duke University in North Carolina and a senior author of the new study. What is, then? The study offers provocative hints about the role of diet and some of the specific foods we eat, as well as about the limits of exercise, and the best ways, in the long run, to avoid and treat obesity. - - - Is diet or inactivity causing obesity? 'There's still a lively debate in public health about the role of diet and activity' in the development of obesity, Pontzer said, especially in wealthy nations. Some experts believe we're exercising too little, others that we're eating too much, and still more that the two contribute almost equally. Understanding the relative contributions of diet and physical activity is important, Pontzer noted, because we can't effectively help people with obesity unless we first tease out its origins. But few large-scale studies have carefully compared energy expenditure among populations prone to obesity against those more resistant to it, which would be a first step toward figuring out what drives weight gain. So, for the new study, Pontzer and his 80-plus co-authors gathered existing data from labs around the world that use doubly labeled water in metabolism studies. Doubly labeled water contains isotopes that, when excreted in urine or other fluids, allow researchers to precisely determine someone's energy expenditure, metabolic rates and body-fat percentage. It's the gold standard in this kind of research. They wound up with data for 4,213 men and women from 34 countries or cultural groups, running the socioeconomic gamut from tribes in Africa to executives in Norway. They calculated total daily energy expenditures for everyone, along with their basal energy expenditure, which is the number of calories our bodies burn during basic, biological operations, and physical activity energy expenditure, which is how many calories we use while moving around. - - - A new theory of how our metabolisms work After adjusting for body size (since people in wealthy nations tend to have larger bodies, and larger bodies burn more calories), they started comparing different groups. Anyone expecting a wide range of energy expenditures, with hunter-gatherers and farmer-herders at the high end and deskbound American office workers trailing well behind, would be wrong. Across the board, the total daily energy expenditures of the 4,213 people were quite similar, no matter where they lived or how they spent their lives. Although the hunter-gatherers and other similar groups moved around far more throughout the day than a typical American, their overall daily calorie burns were nearly the same. The findings, though counterintuitive, align with a new theory about our metabolisms, first proposed by Pontzer. Known as the constrained total energy expenditure model, it says that our brains and bodies closely monitor our total energy expenditure, keeping it within a narrow range. If we start consistently burning extra calories by, for instance, stalking prey on foot for days or training for a marathon, our brains slow down or shut off some tangential biological operations, often related to growth, and our overall daily calorie burn stays within a consistent band. - - - The role of ultra-processed foods The upshot is that 'there is no effect of economic development on size-adjusted physical activity expenditure,' Pontzer says. In which case, the fundamental problem isn't that we're moving too little, meaning more exercise is unlikely to reduce obesity much. What could, then? 'Our analyses suggest that increased energy intake has been roughly 10 times more important than declining total energy expenditure in driving the modern obesity crisis,' the study authors write. In other words, we're eating too much. We may also be eating the wrong kinds of foods, the study also suggests. In a sub-analysis of the diets of some of the groups from both highly and less-developed nations, the scientists found a strong correlation between the percentage of daily diets that consists of 'ultra-processed foods' - which the study's authors define as 'industrial formulations of five or more ingredients' - and higher body-fat percentages. We are, to be blunt, eating too much and probably eating too much of the wrong foods. 'This study confirms what I've been saying, which is that diet is the key culprit in our current [obesity] epidemic,' said Barry Popkin, a professor at the Gillings School of Global Public Health at the University of North Carolina at Chapel Hill and an obesity expert. 'This is a well-done study,' he added. Other experts agree. 'It's clear from this important new research and other studies that changes to our food, not our activity, are the dominant drivers of obesity,' said Dariush Mozaffarian, director of the Food is Medicine Institute at Tufts University in Boston. The findings don't mean, though, that exercise is unimportant, Pontzer emphasized. 'We know that exercise is essential for health. This study doesn't change that,' he said. But the study does suggest that 'to address obesity, public health efforts need to focus on diet,' he said, especially on ultra-processed foods, 'that seem to be really potent causes of obesity.' Related Content He may have stopped Trump's would-be assassin. Now he's telling his story. He seeded clouds over Texas. Then came the conspiracy theories. How conservatives beat back a Republican sell-off of public lands
Yahoo
15-07-2025
- Health
- Yahoo
What causes obesity? A major new study is upending common wisdom.
Obesity is uncommon among Hadza hunter-gatherers in Tanzania, Tsimane forager-farmers in Bolivia, Tuvan herder-farmers in Siberia, and other people in less-developed nations. But it's widespread among those of us in wealthy, highly industrialized nations. Why? A major study published this week in PNAS brings surprising clarity to that question. Using objective data about metabolic rates and energy expenditure among more than 4,000 men and women living in dozens of nations across a broad spectrum of socioeconomic conditions, the study quantified how many calories people from different cultures burn most days. Subscribe to The Post Most newsletter for the most important and interesting stories from The Washington Post. For decades, common wisdom and public health messaging have assumed that people in highly developed nations, like the United States, are relatively sedentary and burn far fewer daily calories than people in less-industrialized countries, greatly increasing the risk for obesity. But the new study says no. Instead, it finds that Americans, Europeans and people living in other developed nations expend about the same number of total calories most days as hunter-gatherers, herders, subsistence farmers, foragers and anyone else living in less-industrialized nations. That unexpected finding almost certainly means inactivity is not the main cause of obesity in the U.S. and elsewhere, said Herman Pontzer, a professor of evolutionary anthropology and global health at Duke University in North Carolina and a senior author of the new study. What is, then? The study offers provocative hints about the role of diet and some of the specific foods we eat, as well as about the limits of exercise, and the best ways, in the long run, to avoid and treat obesity. - - - Is diet or inactivity causing obesity? 'There's still a lively debate in public health about the role of diet and activity' in the development of obesity, Pontzer said, especially in wealthy nations. Some experts believe we're exercising too little, others that we're eating too much, and still more that the two contribute almost equally. Understanding the relative contributions of diet and physical activity is important, Pontzer noted, because we can't effectively help people with obesity unless we first tease out its origins. But few large-scale studies have carefully compared energy expenditure among populations prone to obesity against those more resistant to it, which would be a first step toward figuring out what drives weight gain. So, for the new study, Pontzer and his 80-plus co-authors gathered existing data from labs around the world that use doubly labeled water in metabolism studies. Doubly labeled water contains isotopes that, when excreted in urine or other fluids, allow researchers to precisely determine someone's energy expenditure, metabolic rates and body-fat percentage. It's the gold standard in this kind of research. They wound up with data for 4,213 men and women from 34 countries or cultural groups, running the socioeconomic gamut from tribes in Africa to executives in Norway. They calculated total daily energy expenditures for everyone, along with their basal energy expenditure, which is the number of calories our bodies burn during basic, biological operations, and physical activity energy expenditure, which is how many calories we use while moving around. - - - A new theory of how our metabolisms work After adjusting for body size (since people in wealthy nations tend to have larger bodies, and larger bodies burn more calories), they started comparing different groups. Anyone expecting a wide range of energy expenditures, with hunter-gatherers and farmer-herders at the high end and deskbound American office workers trailing well behind, would be wrong. Across the board, the total daily energy expenditures of the 4,213 people were quite similar, no matter where they lived or how they spent their lives. Although the hunter-gatherers and other similar groups moved around far more throughout the day than a typical American, their overall daily calorie burns were nearly the same. The findings, though counterintuitive, align with a new theory about our metabolisms, first proposed by Pontzer. Known as the constrained total energy expenditure model, it says that our brains and bodies closely monitor our total energy expenditure, keeping it within a narrow range. If we start consistently burning extra calories by, for instance, stalking prey on foot for days or training for a marathon, our brains slow down or shut off some tangential biological operations, often related to growth, and our overall daily calorie burn stays within a consistent band. - - - The role of ultra-processed foods The upshot is that 'there is no effect of economic development on size-adjusted physical activity expenditure,' Pontzer says. In which case, the fundamental problem isn't that we're moving too little, meaning more exercise is unlikely to reduce obesity much. What could, then? 'Our analyses suggest that increased energy intake has been roughly 10 times more important than declining total energy expenditure in driving the modern obesity crisis,' the study authors write. In other words, we're eating too much. We may also be eating the wrong kinds of foods, the study also suggests. In a sub-analysis of the diets of some of the groups from both highly and less-developed nations, the scientists found a strong correlation between the percentage of daily diets that consists of 'ultra-processed foods' - which the study's authors define as 'industrial formulations of five or more ingredients' - and higher body-fat percentages. We are, to be blunt, eating too much and probably eating too much of the wrong foods. 'This study confirms what I've been saying, which is that diet is the key culprit in our current [obesity] epidemic,' said Barry Popkin, a professor at the Gillings School of Global Public Health at the University of North Carolina at Chapel Hill and an obesity expert. 'This is a well-done study,' he added. Other experts agree. 'It's clear from this important new research and other studies that changes to our food, not our activity, are the dominant drivers of obesity,' said Dariush Mozaffarian, director of the Food is Medicine Institute at Tufts University in Boston. The findings don't mean, though, that exercise is unimportant, Pontzer emphasized. 'We know that exercise is essential for health. This study doesn't change that,' he said. But the study does suggest that 'to address obesity, public health efforts need to focus on diet,' he said, especially on ultra-processed foods, 'that seem to be really potent causes of obesity.' Related Content He may have stopped Trump's would-be assassin. Now he's telling his story. He seeded clouds over Texas. Then came the conspiracy theories. How conservatives beat back a Republican sell-off of public lands
The Independent
15-07-2025
- Health
- The Independent
Being a couch potato has long been blamed for obesity - a new study has found the real cause
A new study has turned common conceptions of what causes obesity on its head, revealing that reduced physical activity may not have as large a role in our size as our diets. The study, published this week in PNAS, challenged common wisdom that people in developed nations such as the U.S. are relatively sedentary and burn fewer calories than people in less industrialized countries. Instead, it found that people living in developed nations burned the same amount of calories as people living in less-developed regions, such as farmers, herders and hunters and gatherers, who have much more active lifestyles. The report, which looked at energy expenditure and metabolic rates of more than 4,000 men and women from a variety of nations, suggests that inactivity is not the main cause of obesity both in the U.S. and elsewhere. The groundbreaking research found that what people eat 'plays a far greater role than reduced expenditure in the elevated prevalence of obesity associated with economic development.' Herman Pontzer, a professor and senior author of the study, told the Washington Post that the report's findings are important because they help health officials better know what causes obesity, leading to more successful treatments for patients. Pontzer and his 80-plus co-authors gathered data from labs around the world that use doubly labeled water in metabolism studies, which allows researchers to exactly determine how someone expends energy. The researchers calculated total energy expenditures for 4,213 men and women from 34 countries or cultural groups, and found they were similar, regardless of whether someone was an American office worker or a hunter-gatherer. Regardless of where they lived or how they spent their time, all the people spent similar amounts of energy and burned nearly the same amount of calories each day, the study found. Instead of finding that increased exercise will decrease obesity, the study suggests that 'increased energy intake has been roughly 10 times more important than declining total energy expenditure in driving the modern obesity crisis,' the authors wrote. Meaning, populations with greater rates of obesity are simply eating too much – and likely eating the wrong kinds of foods, Pontzer explained. 'This study confirms what I've been saying, which is that diet is the key culprit in our current [obesity] epidemic,' Barry Popkin, a professor at the Gillings School of Global Public Health at the University of North Carolina at Chapel Hill and an obesity expert, told the Post. 'This is a well-done study,' he added, to which other experts agreed. 'It's clear from this important new research and other studies that changes to our food, not our activity, are the dominant drivers of obesity,' Dariush Mozaffarian, the director of the Food is Medicine Institute at Tufts University in Boston, said. Pontzer, a co-author of the study, emphasized that the study's findings do not mean exercise is unimportant to our overall health. 'We know that exercise is essential for health. This study doesn't change that,' Pontzer said. The study, however, does suggest that to combat obesity, 'public health efforts need to focus on diet,' specifically ultra-processed foods, Pontzer said.
