warum nehme ich trotz sport und kaloriendefizit nicht ab — what are common causes?

The question of why weight loss stalls despite exercise and a calorie deficit is multifactorial. Common causes include inaccurate calorie tracking (underreporting intake, overestimating exercise burn), metabolic adaptation (the body lowers resting energy expenditure during prolonged deficits), hormonal imbalances (thyroid, cortisol, insulin resistance), poor sleep, and chronic stress. Additionally, changes in body composition (gaining muscle while losing fat) can mask fat loss on the scale. Genetic factors (e.g., FTO, PPARG variants) and gut microbiome composition may modulate energy extraction and appetite, but their impact is modest. Consumer DNA tests often overstate these links; clinical assessment (fasting glucose, TSH, etc.) is more reliable. A key safety note: severe calorie restriction can impair metabolism and should be avoided. Evidence for these causes is mixed, as individual responses vary widely.