Evidence check: LCT in the context of Abnehmen

The LCT gene encodes lactase, the enzyme needed to digest lactose (milk sugar). A common variant (e.g., rs4988235) determines whether lactase production persists into adulthood (lactase persistence). In the context of weight loss, LCT is often discussed because dairy products can be part of many diets. However, the evidence for a direct causal effect on weight loss is weak. Individuals with lactose intolerance may avoid dairy, potentially reducing calorie intake – but also risking deficiencies in calcium and vitamin D. Conversely, some studies suggest that moderate dairy consumption in lactase-persistent individuals may enhance satiety and support weight management. The effects are small and highly dependent on overall diet. Consumer DNA tests often include LCT as a 'wellness marker', but its clinical relevance for weight loss is limited. A genetic test alone cannot predict diet success. Instead, individual tolerance and a balanced diet should guide choices. Evidence: human-moderate (observational studies, no RCTs with weight loss as primary endpoint).