Losing weight can be hard
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People with obesity often regain weight after losing weight, possibly in part because of lasting changes in the DNA within fat cells, a finding that could one day lead to new treatments.
About 85% of overweight or obese people have lost at least one tenth of their body weight Recover within one year.
This is partly because it’s difficult to maintain a low-calorie diet long-term, although this may play a relatively small role, says Laura Katharina Hinter at ETH Zurich, Switzerland. “It can’t be that we all don’t have enough willpower to sustain weight loss.”
Research also shows that the brain perceives a drastic drop in body fat as dangerous and dangerous. responds by causing the body to burn less energy.
To learn more about this process, Hinte and her colleagues analyzed fat tissue collected from 20 obese patients before they underwent bariatric surgery, which shrinks the stomach and makes people feel full faster, and again two years later. At least they lost weight at that time. One quarter of original body weight. They also looked at the fat tissue of 18 healthy-weight people.
The researchers sequenced a genetic molecule in fat cells called RNA, which codes for proteins. They found that levels of more than 100 RNA molecules were increased or decreased in obese people compared with healthy-weight people, and that these differences persisted two years after weight loss.
These changes appear to increase inflammation and disrupt Team members say fat cells store and burn fat, both of which increase the risk of future weight gain. Ferdinand von Maynealso at ETH Zurich.
To explore whether these RNA changes could lead to weight regain, the researchers first confirmed that similar changes persisted after weight loss in obese mice. They then fed these mice and healthy-weight mice a high-fat diet for a month. The previously obese mice gained an average of 14 grams, while the other mice gained only 5 grams.
The team also found that fat cells from previously obese mice absorbed more fat and sugar than fat cells from other mice when grown in laboratory dishes. Together, these results suggest that obesity-related RNA changes may increase future weight gain, von Meynn said.
Finally, the team found that molecular tags, or epigenetic marks, on fat cell DNA appear to drive obesity-related RNA changes. They alter RNA levels by changing the structure of the DNA that encodes them.
While the study didn’t look for these molecular signatures in the people they studied or examine whether they regained the weight they lost, the findings may be transferable from mice to humans, said Henriette Kirchner at the University of Lübeck, Germany.
She said this is based on similarities between the physiology of these species and how the environment changes the way their genes work, known as epigenetics. In the coming decades, drugs targeting epigenetics may help treat obesity, Kirchner said.
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