Scientists Don’t Agree on What Causes Obesity, but They Know What Doesn’t

And that was predictable from a Left-leaning group. Leftists regularly shy away from individual responsibility. They tend to blame "society" for personal failings. And the idea that people have no personal control over obesity is bunk. The media are full of stories about people who have changed their behavior and lost a lot of weight as a result. I am myself a lot lighter than I used to be. Though I went down a very hard road to get there

LONDON — A select group of the world’s top researchers studying obesity recently gathered in the gilded rooms of the Royal Society, the science academy of Isaac Newton and Charles Darwin, where ideas like gravity and evolution were once debated.

Now scientists were arguing about the causes of obesity, which affects more than 40 percent of U.S. adults and costs the health system about $173 billion each year. At the meeting’s closing session, John Speakman, a biologist, offered this conclusion on the subject: “There’s no consensus whatsoever about what the cause of it is.”

That’s not to say the researchers disagreed on everything. The three-day meeting was infused with an implicit understanding of what obesity is not: a personal failing. No presenter argued that humans collectively lost willpower around the 1980s, when obesity rates took off, first in high-income countries, then in much of the rest of the world. Not a single scientist said our genes changed in that short time. Laziness, gluttony and sloth were not referred to as obesity’s helpers. In stark contrast to a prevailing societal view of obesity, which assumes people have full control over their body size, they didn’t blame individuals for their condition, the same way we don’t blame people suffering from the effects of undernutrition, like stunting and wasting.

The researchers instead referred to obesity as a complex, chronic condition, and they were meeting to get to the bottom of why humans have, collectively, grown larger over the past half century. To that end, they shared a range of mechanisms that might explain the global obesity surge. And their theories, however diverse, made one thing obvious: As long as we treat obesity as a personal responsibility issue, its prevalence is unlikely to decline.

A nutritional biologist presented ?th?e idea that all the carbohydrates and fat in our food today dilute the protein our bodies need, driving us to eat more calories to make up for the discrepancy. An endocrinologist spoke of the scientific model behind the low-carb diet approach, suggesting eating patterns heavy in carbohydrates are uniquely fat promoting, while an evolutionary anthropologist argued many lean hunter-gatherer societies ate a lot of carbohydrates, with a special affinity for honey.

Others suggested the problem is ultraprocessed foods, the prepared and packaged goods that make up more than half of the calories Americans consume. A physiologist shared his randomized control trial showing people eat more calories and gain more weight on ultraprocessed diets compared with whole-food diets of the same nutrient composition. But it’s still unclear why these foods drive people to eat more, he said.

The mystery could be explained by the thousands of toxic substances ultraprocessed foods can carry in the form of fertilizers, insecticides, plastics and additives, argued one biochemist. Her research in cells has shown these chemicals interfere with metabolism.

Still others thought perhaps the problem is less about what we’re eating and more about what we’re not. An ethologist shared her work on the link between food insecurity and obesity in birds. When food becomes scarce, the animals eat fewer calories but gain more weight. Studies in humans have also found a “robust” association between food insecurity and obesity, she said — the so-called hunger obesity paradox.

To add to the complexity, the researchers made it clear that obesity can’t be thought of as one condition. They spoke of rare cases caused by single gene mutations or disorders; more commonly, obesity is believed to arise because of still murky gene-environment interactions. Perhaps they should have been talking about obesities the whole time.

By the end of the conference, the attendees were no closer to a unifying theory for the global rise in obesity — a condition that’s been with humans since at least Hippocrates but started to become widespread only after the debut of MTV. Yet in that short period, scientists, including many in the room, ??have learned a lot.

They’ve identified more than a thousand genes and ??variants that increase a person’s obesity risk. They’ve figured out that body fat is much more than a storage depot for energy and that not everyone with obesity ?goes on to develop its associated complications, which include cancer, Type 2 diabetes, high blood pressure, heart attack, stroke and premature death. They’ve made remarkable progress mapping out how the brain orchestrates feeding and adapts to different diets, altering food preferences along the way. But ?precisely what changed in recent? history to affect these complex biological systems, the scientists couldn’t concur.

https://www.nytimes.com/2022/11/21/opinion/obesity-cause.html

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