The yo-yo effect of dieting may not be as harmful as previously thought, according to a new analysis

The Myth of the Yo-Yo Effect Challenged

The desire to lose weight often runs up against a major psychological barrier: the fear of gaining it all back. According to an article published on June 26, 2026, by Sanjana Gajbhiye, a journalist for Earth.com, this particular fear has shaped dietary advice for many years. Those affected dread ending up in a situation worse than the one they started in.

The usual warning has long dominated medical and public discourse. Drastic diets followed by weight regain were treated as a formidable trap that had to be avoided at all costs. The cycle of weight loss and regain—commonly known as the yo-yo effect—seemed to carry the risk of irreversible damage to the body.

Two scientists recently reviewed previous studies on this phenomenon. The conclusions of their literature review aim to reassure the many people who are anxious about their eating habits. These new findings mark a clear break from decades of systematic warnings.

The benefits of weight loss outweigh the risks of regaining weight

The researchers analyzed a wide range of evidence, including observational studies, clinical trials, and animal studies. Their observations focused on body weight, body composition, and metabolism. Professor Faidon Magkos of the University of Copenhagen led this in-depth analysis with a colleague.

Public concerns appear disproportionate to the current scientific evidence. "Many people refrain from trying to lose weight because they fear that subsequent weight regain will harm their bodies or their metabolism. Our review indicates that these concerns are largely unfounded," explains Professor Magkos. The researcher urges people to reconsider the balance between the benefits and drawbacks of dieting.

The period spent at a lower weight brings real benefits to the body. “In most cases, the benefits of weight loss outweigh the potential risks of subsequent weight regain.” He then clarifies the concept of risk and return to baseline: “When the weight returns, you approach a risk level similar to what it was before—not beyond it. “There’s a crucial difference between losing benefits and causing harm,” the scientist states.

The Flaws in Previous Diet Studies

Yo-yo dieting has earned a grim reputation over the years. Some experts even claimed that this weight fluctuation was more harmful to health than simply remaining overweight. Concerns about the potential harm quickly mounted, ranging from increased body fat and muscle loss to a slowed metabolism and heightened risks of type 2 diabetes and heart disease.

Much of this alarm, however, rests on shaky ground. The data frequently comes from individuals’ self-reports of their own weight, an indicator that is often unreliable. Distinguishing cause from effect is complex, as the numbers may show a link without revealing its true origin. In particular, it remains difficult to determine whether a person has lost weight voluntarily or due to an underlying medical condition.

“When we take into account pre-existing conditions, aging, and overall exposure to obesity, the purported harmful effects of yo-yo dieting largely disappear,” explains Professor Norbert Stefan of the German Diabetes Research Center. Once these multiple factors are ruled out, the perceived danger decreases considerably, proving that the harm was often not related to the diet itself.

The Real Culprit and the Impact on Modern Treatments

Several large-scale studies point to a much simpler culprit in the development of metabolic diseases. The absolute amount of excess weight—rather than its increase or decrease—appears to be the real driver of health problems. This discovery shifts the blame from the cycle of dieting to obesity itself. The focus should be on reducing excess weight rather than monitoring every fluctuation.

This issue is of paramount importance today, given the rapid proliferation of weight-loss drugs. Many users will pause or stop their treatment, which frequently leads to regaining a large portion of the weight lost. The authors note that this rebound should not be interpreted as a harmful event. Even a temporary period of improved health, characterized by more stable blood sugar levels and increased mobility, has real value for the body.

Reframing this situation alleviates a genuine concern for many patients. The fear of a possible relapse should not prevent a person from following a beneficial treatment. Most individuals who succeed in maintaining their weight have often stumbled several times before. An attempt that ends in weight regain is frequently a step on the path to success, transforming what is perceived as a simple failure into a useful learning experience.

A New Perspective for Patients

The study is presented in a “Personal View” format, in which scientists evaluate existing evidence to offer a thoughtful assessment. Other researchers might interpret the same data differently. The authors of this paper, published in the journal The Lancet Diabetes and Endocrinology, present arguments rather than a definitive verdict. None of this constitutes a green light for reckless, drastic diets; gradual change remains preferable to extreme fluctuations.

The findings are primarily intended to encourage individuals who are trying to lose weight to continue their efforts without feeling ashamed. “Overweight people should not be discouraged from trying to lose weight, even if they struggle to maintain it in the long term,” the researchers note. They add a key piece of advice for overall perseverance: “Unsuccessful attempts at weight loss are not harmful, but giving up entirely can be.”

Every body reacts differently to dietary changes and therapeutic approaches. Fluctuations are not the destructive factors that society once believed them to be, allowing for a more relaxed approach to the obstacles encountered along the way. For any medical questions, consult a qualified healthcare professional.

Source: earth.com

The yo-yo effect of dieting may not be as harmful as previously thought, according to a new analysis