Why Your Body ‘Remembers’ Fat and How It Affects Weight Loss: Insights from Science

Obesity and Weight Regain: Understanding the Yo-Yo Effect

Obesity can lead to long-lasting changes in fat cells. These changes make it easier to regain weight after dieting. Researchers at ETH Zurich discovered this mechanism in both mice and humans.

What is Epigenetics?

Epigenetics refers to chemical markers on our DNA that do not change the DNA sequence but influence gene activity. Unlike our genetic code, which we inherit from our parents, these markers can change based on our environment, diet, and health.

Epigenetic Memory of Obesity

The researchers studied overweight mice to understand why losing weight is often followed by regaining it. They found that obesity causes specific epigenetic changes in fat cells. Remarkably, these changes can remain long after weight loss. As a result, fat cells retain a “memory” of the obese state, making it easier to regain weight when high-fat foods are reintroduced.

Researchers also examined fat tissue samples from formerly overweight individuals who had weight-loss surgeries, like gastric bypass. Similar patterns in gene expression were found, supporting the findings from the mice studies.

Importance of Prevention

The researchers did not determine how long fat cells remember obesity, but they noted that these cells can live for about ten years. Currently, it is not possible to erase these epigenetic changes with medication. Therefore, preventing obesity is crucial. Avoiding weight gain in the first place is the most effective way to prevent the yo-yo effect.

This information is particularly important for children, teenagers, and their families. The research highlights that fat cells are not the only type of cell that may have a memory of obesity. Other cells in the body might also contribute to the yo-yo effect, and the researchers plan to investigate this further.

Conclusion

ETH Zurich’s research shows that obesity leaves an epigenetic mark on fat cells, making weight regain more likely. Early prevention of obesity remains essential, as current methods cannot reverse these cellular changes.