What to watch with FUT2 and weight loss?

FUT2 (fucosyltransferase 2) determines secretor status and influences vitamin B12 absorption and gut microbiome composition. Some studies suggest non-secretors (homozygous for the inactive variant rs601338) may have lower B12 levels and altered microbiota, which could theoretically affect energy metabolism and weight regulation. However, evidence is moderate: associations are small, not consistently replicated, and overshadowed by diet and lifestyle. MyBody-X may test FUT2, but results should not be the sole basis for weight loss decisions. B12 deficiency should be confirmed via blood tests. Practical advice: a balanced diet with adequate B12 (meat, fish, eggs, fortified foods) is recommended for everyone regardless of FUT2 status. Genetics is just one small piece of the puzzle.