yoyoeffect

The yo-yo effect, also called weight cycling or yo-yo dieting, describes repeated cycles of losing and regaining body weight. It most commonly occurs after dieting attempts or rapid fat-loss regimens, rather than during continuous, sustainable weight management.

Weight loss triggers physiological and behavioral responses that can promote regain. Energy expenditure often falls with caloric restriction, a phenomenon known as metabolic adaptation. Hormonal changes may increase hunger (for example, rising ghrelin and falling leptin), while loss of lean body mass can reduce resting metabolic rate. When restricting ends and normal or increased eating resumes, the energy surplus can lead to weight regain, sometimes beyond the previous level. Behavioral, environmental, and psychosocial factors also contribute to cycling.

Evidence on health effects is nuanced. Short-term weight loss is achievable, but long-term maintenance after dieting is challenging, and net weight change over many years is frequently small. Some observational studies associate weight cycling with higher risks of cardiovascular disease, type 2 diabetes, and mortality, but causality remains uncertain and results vary by population and study design. The pattern may differ among individuals, influenced by genetics, age, starting weight, and lifestyle.

Prevention and management emphasize sustainable approaches. Key strategies include gradual, realistic weight loss; ongoing physical activity with resistance training to preserve lean mass; adequate protein intake; behavioral support and stress management; regular monitoring and adjustments to maintain adherence. Emphasis on long-term lifestyle change rather than extreme diets reduces the likelihood and impact of weight cycling.