How fat ‘memory’ in cells can be a cause of yo-yo dieting

It’s an age-old problem for dieters: losing a few pounds and then quickly gaining them back.

But now experts have discovered that our fat tissue retains a ‘memory’ of obesity that persists even after weight loss, which could increase the chances of regaining the excess weight.

The findings may help explain the so-called “yo-yo” effect often seen when dieting, the researchers said.

Scientists analyzed cells from body fat tissue in 18 people with a healthy body weight, as well as in 20 obese people before and after they lost weight after bariatric surgery.

They found that the fat tissue showed changes in RNA sequences – molecules that contain instructions for making proteins – even after significant weight loss.

Analyzes were carried out in lean, obese and previously obese mice and revealed similar changes that appeared to be linked to disturbances in some metabolic processes: chemical reactions that convert food and drink into energy.

These may contribute to weight gain after dieting, the authors said.

The team from ETH Zurich, a university in Switzerland, concluded that targeting these changes in the future could improve weight management in the long term.

Experts have discovered that our fat tissue retains a ‘memory’ of obesity that persists even after weight loss, which could increase the chance of regaining the excess weight (file image)

Scientists analyzed cells from body fat tissue in 18 people with a healthy body weight, as well as 20 obese people before and after they lost weight after bariatric surgery (file image)

Writing in the journal Nature, they said: ‘Reducing body weight to improve metabolic health and associated comorbidities is a primary goal in the treatment of obesity.

‘However, maintaining weight loss is a significant challenge, especially because the body appears to maintain a… memory that defends against changes in body weight.

‘These changes… contribute to the problematic ‘yo-yo’ effect often seen with dieting.’

Although their research focused on obesity, it’s possible that a similar type of cell memory could also play a role in other contexts, such as alcohol or nicotine addiction, they added.

A previous study found that yo-yo weight loss can still provide an overall health boost.

Scientists from the University of Oxford found that people who struggle to maintain their target weight in the long term are still healthier than before they lost weight, even if they gain some weight back.

The study of more than 50,000 obese people found that those who regained weight after dieting still had lower blood pressure and cholesterol levels than before they lost any weight.

And the findings provide reassurance that any form of weight loss is beneficial, even if there is some regression.