We’re beginning to understand why some people regain the weight they lost

Obese people who lose weight often wear them again, which may be driven in part by permanent changes to the DNA within their fat cells, a discovery that could one day lead to new treatments.

About 85 percent of people who are overweight or obese lose at least one-tenth of their body weight Recovered within a year.

This is partly because it is difficult to maintain a low-calorie diet for a long period of time, although that probably plays a relatively small role, he says. Laura Katharina Hint At the Federal Institute of Technology Zurich in Switzerland. “It can’t be that we all don’t have enough willpower to keep the weight off.”

Studies have also shown that the brain interprets a sharp decrease in body fat as dangerous It responds by making the body burn less energy.

To learn more about this process, Henty and her colleagues analyzed adipose tissue collected from 20 obese people before undergoing bariatric surgery, which shrinks the stomach to make people feel full sooner, and again two years later, when they had lost at least A quarter of the initial body weight. They also studied the adipose tissue of 18 people of a healthy weight.

The researchers sequenced a type of genetic molecule called RNA, which encodes proteins, in fat cells. They found that obese people had increased or decreased levels of more than 100 RNA molecules compared to people of a healthy weight, and these differences persisted for two years after weight loss.

These changes appear to increase inflammation and disrupt how it occurs Fat cells store and burn fat, both of which increase the risk of future weight gain, the team member says Ferdinand von MeinAnd also at the Federal Institute of Technology in Zurich.

To explore whether these RNA changes might lead to rebound weight gain, the researchers first confirmed that similar changes persisted after obese mice lost weight. They then fed these mice and mice of a healthy weight a high-fat diet for one month. While the obese mice gained an average of 14 grams of weight, the other mice gained only 5 grams.

The team also found that fat cells from previously obese mice consumed more fat and sugar when growing in a laboratory dish than those from other mice. Together, the results show how obesity-related RNA changes may fuel weight gain in the future, von Meyne says.

Finally, the team found that molecular marks, or epigenetic marks, found on the DNA in fat cells appear to lead to the RNA changes associated with obesity. These changes alter RNA levels by altering the structure of the DNA that encodes it.

While the study didn’t look for these molecular markers in the people it studied, or examine whether they regained the weight they lost, the findings from mice could potentially translate to humans, he says. Henriette Kirchner At the University of Lübeck in Germany.

She says this is based on similarities between the physiology of these species and how the environment can change the way their genes work, known as epigenetics. In the coming decades, drugs that target epigenetics could help treat obesity, Kirchner says.

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