What to watch with MY FOODBOOK and weight loss?

MY FOODBOOK by MyBody-X is a test that claims to provide personalized dietary recommendations based on DNA and/or microbiome data. For weight loss, the scientific basis is weak. Most claimed 'diet types' (e.g., 'carb-sensitive') are not supported by randomized controlled trials. GWAS show small effects of individual genes (e.g., FTO, MC4R) on weight, but these are negligible compared to lifestyle factors. Microbiome tests provide a snapshot of gut bacteria, but their clinical relevance for weight loss is unclear. MyBody-X itself states the test does not diagnose disease. What to watch: Results may be motivating, but they do not replace evidence-based nutrition counseling. Marketing claims like 'genetically determined carb sensitivity' are exaggerated. A sound approach to weight loss remains: calorie balance, balanced diet, exercise, and behavior change. The test can serve as a 'nudge' but not as a scientifically validated strategy.