Why is it so difficult to lose weight? The cause may be “fat cells” – First post

Losing weight is a difficult process, but keeping it off can be even more difficult. Researchers have been looking into why this happens and may have found the answer.

Research shows that even after weight loss, fat cells retain a “memory” of obesity. This finding explains why maintaining weight loss can be so difficult.

The results show that obesity alters the epigenome, a system of chemical markers that regulate gene function. These changes affect how fat cells work, sometimes affecting their normal function.

It is noteworthy that even procedures such as weight loss surgery do not eliminate these genetic changes. The body’s epigenetic connections to obesity persist, which may increase the likelihood of weight regain.

Dr Laura Hinte, biologist at ETH Zurich and co-author of the study, said: Nature The results show that people trying to lose weight often require long-term care to avoid regaining weight. “That means you potentially need more help,” she said. “It’s not your fault.”

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How was the study conducted?

To understand why weight often returns quickly after loss, Laura Hint and her team studied the fat tissue of two groups: severely obese people and a control group who had never been obese. Their analysis revealed differences in gene activity between the two groups. Some genes were more active in the fat cells of obese people, while others were less active. Nature the report says.

Even after weight loss surgery, this pattern persisted. Two years after the weight-loss surgery, the participants had lost significant weight, but the gene activity in their fat cells still showed patterns associated with obesity. Similar results were observed in mice that lost significant weight.

In both humans and mice, genes that became more active during obesity were associated with inflammation and fibrosis—the formation of tough, scar-like tissue. Meanwhile, genes that support normal fat cell function became less active. Further studies in mice revealed that these changes were associated with shifts in the epigenome, a system that greatly influences gene activity, including whether genes are turned on or off.

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To test the sustainability of these changes, obese mice were put on a diet. Several months after they regained their lean body, the changes in their epigenomes continued, as if the fat cells retained a “memory” of obesity.

How long does the body “remember” obesity?

The duration of the body’s “memory” of obesity remains uncertain, said Ferdinand von Meyenne, an epigenome specialist at ETH Zurich and co-author of the study. Nature.

“There may come a point when that memory is lost,” he said. – But we don’t know.

To study the impact of this memory, the researchers examined fat cells from mice that had lost weight after becoming obese. These cells absorbed more sugar and fat than cells from a control group of mice that had never become obese. Additionally, previously obese mice gained weight faster on the high-fat diet compared to controls.

It’s worth noting, however, that outside experts said the study did not establish that epigenetic changes caused these physical effects.

Biologist Evan Rosen of Beth Israel Deaconess Medical Center in Boston, who specializes in adipose tissue, told Nature that while the study provides a valuable list of epigenetic changes in fat cells, identifying which ones directly influence cell behavior will be challenging.

“This is not yet a cause-and-effect relationship,” said Ferdinand von Meyenne. “It’s a correlation. … We’re working on it.”

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What do the results mean?

Von Meyenne said preventing obesity in the first place is important. While people “can (stay) frugal, it takes a lot of effort and energy to do so.”

He said the team’s findings could help reduce the stigma associated with obesity. “It’s a complex condition and it’s not just about willpower,” he said.

The research could lead to more effective weight control programs, although the cellular memory of obesity may fade over time. “It’s possible that maintaining a low or healthy body weight long enough to erase the memory,” Hinte said. Guardian.

Professor Henriette Kirchner from the University of Lübeck called the results “very plausible.” She told the British daily: “I’m convinced this plays a major role in the yo-yo effect of dieting… Researchers show convincingly that memories become harder to erase the longer you are obese.”

Weight regain is common among people who lose weight through dieting or after using weight loss methods such as
Vegovaespecially when these interventions cease.

David Benton, emeritus professor at Swansea University and author of the 2024 book Solving the Obesity Crisis: Beyond Failed Approaches to Long-Term Solutions, said more than 100 factors contribute to obesity.

He said Guardian“Obesity means you consume more calories than you burn. When dieting robs you of energy, you lose weight.”

“However, the mantra is that diets fail. They fail because to avoid regaining lost weight, you need to permanently change your diet. Most often, after finishing a diet, we return to the lifestyle that caused the problem in the first place. The result is a yo-yo diet.

Understanding how fat cells retain the memory of obesity could pave the way for improved treatments and provide hope for millions of people struggling to effectively control their weight.

With the participation of agencies