It can be hard to keep weight off Tero Vesalainen/Getty Images People with obesity who lose weight often put it back on, which may partly be driven by lasting changes to the DNA within their fat cells, a discovery that could one day lead to new treatments. Around 85 per cent of people with overweight or obesity who lose at least a tenth of their body weight regain it within a year . That is partly because it is hard to maintain low-calorie diets for a long period of time, though that probably plays a relatively small role, says Laura Catharina Hinte at the Federal Institute of Technology Zurich in Switzerland.
“It can’t be that we all don’t have enough willpower to maintain lost weight.” Studies have also shown that the brain interprets a sharp drop in body fat as dangerous and responds by making the body burn less energy . To learn more about this process, Hinte and her colleagues analysed fat tissue collected from 20 people with obesity just before they had bariatric surgery, which shrinks the stomach to make people feel fuller sooner, and again two years later, when they had lost at least a quarter of their initial body weight.
They also looked at fat tissue from 18 people with a healthy weight. The researchers sequenced a type of genetic molecule called RNA , which encodes proteins, in fat cells. They found that people with obesity had increased or decreased levels of more than 100 RNA molecules compared with people of a healthy weight, and these differences persi.