What should I know about warum nehme ich trotz kaloriendefizit zu?

The question of why one gains weight despite a calorie deficit is complex and requires an honest look at the evidence. First, the calorie balance is physically fundamental: if the body truly takes in less energy than it expends, it cannot gain mass in the long term. However, short-term weight fluctuations due to water retention (e.g., from salt, carbohydrates, menstrual cycle) are common and can mimic fat gain. Inaccurate tracking of calorie intake (estimation errors, hidden calories in drinks or sauces) or expenditure (overestimating exercise) is also typical. Medical causes such as hypothyroidism, insulin resistance, or medications (e.g., corticosteroids, antidepressants) can affect metabolism, but the energy balance remains physically valid. Genetic factors (e.g., FTO, MC4R) usually have small effects and do not explain large deviations. The evidence here is mixed: strong for measurement error and water retention, moderate for metabolic adaptation, weak for genetic causes. Without blood tests and precise logs, the cause often remains unclear. A doctor visit and nutritional counseling are advisable before drastic measures.