Yo-yo dieting may strip away muscle as well as fat, study suggests
Repeated cycles of weight loss and regain may lead to a loss of lean muscle, not just body fat, according to new research on yo-yo dieting.
People who repeatedly lose and regain weight, a pattern often described as yo-yo dieting, may be shedding more than body fat. New research highlighted by Medical Xpress suggests that each cycle of weight loss and regain can also strip away lean muscle tissue, raising concerns about the long-term effects of repeated dieting.
What the research found
Researchers examined how repeated dieting affected body composition rather than simply tracking the number on the scale. They found that when weight was lost and then regained, a meaningful portion of that regained weight was not fat but muscle. Over several cycles, this gradual loss of lean tissue can leave dieters with a higher proportion of body fat, even if their overall weight returns to a similar level.
Why muscle matters
Skeletal muscle plays a key role in metabolism, strength, mobility, and blood-sugar regulation. When muscle mass declines, resting metabolic rate can drop, making future weight management more difficult. Reduced lean tissue has also been linked in other studies to weaker long-term outcomes in weight maintenance, as well as broader concerns about nutrition and health that parallel findings in analyses of ultra-processed food consumption.
Implications for dieters
Experts generally recommend that people aiming to lose weight focus on preserving muscle through adequate protein intake and resistance training, rather than relying on extreme calorie restriction. Approaches that emphasise nutritional quality, including dietary strategies that support overall metabolic health, may help protect lean tissue during weight loss.
- Yo-yo dieting can reduce lean muscle along with fat.
- Muscle loss can slow metabolism and make weight regain more likely.
- Protein intake and strength training are commonly advised to protect muscle during dieting.