warum nehme ich nicht ab — when to see a doctor?

The question 'why am I not losing weight' is multifactorial. While energy balance (calories in vs. out) is fundamental, many factors influence weight loss: metabolic adaptation, hormonal fluctuations (cortisol, insulin, leptin), sleep quality, stress, medications, and undiagnosed conditions (hypothyroidism, insulin resistance, PCOS). Inaccurate tracking of food intake or overestimation of exercise is also common. When to see a doctor? If you have followed a consistent calorie-controlled diet and regular exercise for 3–6 months without significant progress, or if you experience symptoms like fatigue, cold intolerance, hair loss, excessive thirst, or mood changes. A physician can order blood tests (TSH, fT3, fT4, fasting glucose, HbA1c, vitamin D, iron panel) to rule out endocrine or metabolic disorders. Consumer DNA tests for weight loss (e.g., FTO variants) have small effect sizes and are not clinically actionable. Do not start extreme diets or supplements without medical supervision. Evidence is based on clinical practice guidelines and observational studies; no direct RCTs address this specific question.