Diet not lack of exercise drives obesity, a new study finds : NPR

Back in the 1800s, obesity was barely present in the United States. Over the last century, it has become common here and in other developed countries, but remains rare among people living a more traditional lifestyle. Hadza Hunter-Gatherers of Tanzania.

So what has changed? One general explanation is that as society develops, they tend to be more sedentary and people are less aggressive. This means that you burn less calories every day and contribute to an energy imbalance that leads to weight gain over time. Herman Ponzer says, Professor of evolutionary biology and global health at Duke University is studying how human metabolism evolved.

but, Major new research Published in the journal pnas, The international team of Ponzer and collaborators discovered that this is not the case. They compared daily total calorie burns of people from 34 different countries and cultures around the world. Officials have run the spectrum from hunter-gatherers and agricultural groups with low obesity rates to people who are more sedentary jobs in places like Europe and the United States, where obesity is widespread.

“Amazingly, what we found is that, in reality, the total calories per day are really similar in these groups, despite the fact that lifestyles and activity levels are really different,” says Ponzer.

And that finding provides strong evidence that diet is the major driver of weight gain and obesity in our modern world, rather than lack of physical activity.

“This really flies in the face of something that many of us today thought anecdotal assumptions. Deirdre Tobiasobesity and nutritional epidemiologist at Brigham and Women’s Hospital in Boston and Harvard Chan School of Public Health. Tobias was not involved in the new research.

Different activity levels, same calorie burning

In this study, researchers looked at data from over 4,200 adult men and women. Study participants were able to drink special water containing isotopes that appeared in the urine. These isotopes allow scientists to accurately determine how much energy a person consumes. Not only are active movements, but also the energy required to maintain the heartbeat, the function of the nervous system, and Stay alive in general.

“This allows people to measure very accurately how many calories they burn per day over a week,” Ponzer says.

As they adjusted to their body size, Ponzer and his colleagues found that people in the high obesity population had slightly less energy per day than people in the low-weight population. These differences in energy expenditure, he says, did not contribute much to differences in obesity rates between populations.

For example, if you’re burning the same amount of daily calories all day as your typical office worker, scientists say that suits what scientists are learning about how our bodies burn calories. Ponzer’s previous research suggests that our bodies tend to regulate the way our bodies consume energy.

“So, when we burn more energy every day with physical activity, exercise, after a while, our bodies adjust our bodies to other tasks that we don’t notice what’s happening in the background and spend less energy,” says Ponzer.

Change the obesity message

New discoveries have a great impact on obesity. If the difference in Calorie Burn cannot explain why obesity is higher than in other countries, it must be something else. “And it’s going to be a meal,” says Tobias, who praised the design of the new research.

“It’s 100% of the meal,” I agree. Dr. Dariush Mozaffarian, Friedman Food Director of Nutrition Science and Policy at Tufts University is the Medical Institute. “And I’m asking, what is it about diet?”

Mozaffarian was not involved in the study, but he says it will be added to other recent studies that suggest that food is the biggest factor in obesity. He points out that there have been a significant change in our food supply over the last few decades. Ultra processed foods. In a subanalysis of some data on the population, Ponzer and his colleagues found that people in countries who get more calories from ultra-highly processed foods tend to have more obesity and higher body fat percentages.

“For decades, we’ve been telling Americans that you’re lazy and that it’s your fault, you’re not moving enough, you’re eating too much,” says Mozafarian. “And I think what this research shows is that there’s really complex biology happening and our food is driving this.”

Well, this doesn’t mean there’s no The reason for exercising. After all, that’s true Good for our spirit and Physical health In so many ways that it has nothing to do with weight.

But that means we can’t overtake a bad diet. Ponzer says that if you want to tackle obesity, the public health message should focus on changing what’s on our plates.