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Yo-yo dieting may pose different risks depending on starting weight

Repeatedly losing and regaining weight, known as yo-yo dieting, may carry different health risks depending on whether a person starts at a normal weight or with obesity. New expert analysis suggests that weight cycling might be less harmful for those with obesity but could increase obesity risk in people who begin at a normal weight.

NeoMD Editors · 2026-10-17 · 02:43 AM EDT

For information, not personal medical advice. Discuss treatment decisions with a qualified clinician.

The quick read

Key takeaways

Yo-yo dieting involves repeated cycles of weight loss and regain, common among people who struggle to maintain weight loss over time.
For individuals with obesity, weight cycling may be less harmful to metabolic health than previously thought, while it may increase obesity risk for those starting at a normal weight.
Most evidence comes from observational studies that show associations but cannot prove causation; more research is needed to understand biological mechanisms and risks of weight cycling.

Editorial illustration for Yo-yo dieting may pose different risks depending on starting weight — AI-generated editorial illustration.

What is yo-yo dieting?

Yo-yo dieting refers to repeated cycles of losing weight and then regaining it back again. This pattern is common among people who attempt to lose weight but struggle to maintain the loss over time.

Experts weigh in on health risks

Researchers Norbert Stefan and Faidon Magkos from the University of Copenhagen published an assessment in Nature Reviews Endocrinology discussing the health effects of weight cycling based on a person’s starting weight.

They explain that for individuals living with obesity, these fluctuations seem to be less harmful than previously thought. However, for people who begin at a normal weight, repeated weight gain and loss could increase their long-term risk of developing obesity.

What does the evidence show?

The conclusions are drawn from a review of existing research, which considers observational studies tracking people over time. Such studies can show associations but cannot definitively prove that yo-yo dieting causes specific health outcomes.

Supporting editorial illustration for Yo-yo dieting may pose different risks depending on starting weight — AI-generated editorial illustration.

For individuals with obesity, the data suggest that weight cycling may not worsen metabolic health as much as once feared. Conversely, in people with a normal weight, frequent weight fluctuations might contribute to gradually gaining excess weight and obesity later on.

Limitations and unknowns

Because most evidence comes from observational studies, it is difficult to separate cause and effect—meaning, it is unclear whether weight cycling directly leads to poor health outcomes or if other factors are involved.

More research is needed to understand the underlying biological mechanisms and to clarify whether certain patterns or amounts of weight cycling are more harmful than others.

What could this mean for individuals?

People with obesity who experience some weight regain after dieting may not face as many additional risks as once thought, but this does not eliminate the benefits of sustained, healthy weight loss.

For those at a normal weight, repeated dieting and regaining weight could raise the risk of becoming obese. This highlights the importance of maintaining a stable healthy weight rather than cycling through weight loss and gain.

People concerned about their weight or weight cycling should consult healthcare professionals for personalized advice.

Source: Medical Xpress