Why Yo-Yo Dieting Might Not Be So Bad After All, According to New Research

 

New Study Suggests Yo-Yo Dieting May Have Surprising Health Benefits

For years, yo-yo dieting—the cycle of losing weight through dieting and then gaining it back—has been viewed as harmful to health. Many earlier studies warned that repeated weight fluctuations could raise the risk of serious conditions such as heart disease, stroke, diabetes, and high blood pressure.

However, new research is challenging that long-standing belief.

A recent study published in BMC Medicine suggests that repeated attempts to lose weight may actually provide long-term health benefits, particularly by reducing visceral fat, the dangerous fat that accumulates around internal organs in the abdomen.

Looking Beyond the Number on the Scale

The study is being described as the largest long-term MRI-based trial examining repeated weight-loss attempts. Its findings indicate that even when people regain weight after dieting, their bodies may retain important metabolic improvements.

According to Professor Iris Shai, the study’s lead investigator, focusing only on body weight can miss the bigger picture.

She explained that maintaining dedication to healthier eating habits can create what researchers call “cardiometabolic memory.” This means the body may remember and benefit from previous healthy lifestyle changes—even after weight is regained.

In other words, trying again after a dieting setback might still improve long-term health.

Health Improvements Can Persist After Weight Regain

Lead author Hadar Klein, a doctoral researcher at Ben-Gurion University of the Negev, emphasized that body weight alone doesn’t reveal everything happening inside the body.

Key indicators like visceral fat levels and metabolic biomarkers can improve significantly during dieting—and those improvements may remain even if the scale goes back up.

This means success shouldn’t be measured solely by the number on the scale.

How the Study Was Conducted

Researchers followed approximately 300 participants who took part in two separate dietary intervention trials, each lasting 18 months.

The participants were observed over a long period, including follow-ups five and ten years later. The trials primarily focused on a Mediterranean-style diet combined with physical activity, compared with standard control diets.

Using detailed MRI scans, scientists measured participants’ abdominal fat levels and metabolic health markers before and after each program.

Surprising Results from the Second Weight-Loss Attempt

When participants entered the second intervention, most had regained the weight they had previously lost. However, the scans revealed something unexpected.

Despite returning to their original body weight, participants showed healthier abdominal fat profiles and improved metabolic markers compared with their starting point years earlier.

The improvements were significant:

• 15% to 25% better metabolic indicators

• Improved insulin sensitivity

• A healthier cholesterol and lipid profile

These findings support the idea that previous weight-loss efforts can leave behind a positive metabolic impact.

Repeated Attempts Still Deliver Long-Term Gains

Interestingly, participants lost slightly less weight during their second diet attempt compared to the first. Even so, they still experienced better long-term health outcomes.

Five years after completing the second program, those who had participated twice showed:

• Less weight regain

• Lower accumulation of abdominal fat

compared with individuals who only joined a weight-loss program once.

What This Means for People Trying to Lose Weight

The results offer an encouraging message for anyone who has struggled with dieting.

Instead of viewing weight regain as complete failure, repeated efforts to improve diet and lifestyle may continue to benefit the body over time. Even if the scale fluctuates, internal health markers can still move in the right direction.

The research team included scientists from several major institutions, including Harvard’s Department of Nutrition, University Hospital Leipzig in Germany, and Tulane University’s School of Public Health.

Their findings suggest that persistence—not perfection—may be the key to long-term metabolic health.