Is HLA-DQ2 useful for weight loss?

HLA-DQ2 is a genetic marker strongly associated with celiac disease, not directly with weight loss. In individuals with undiagnosed celiac disease, a gluten-free diet can lead to weight normalization, but this applies only to those affected. For the general population, HLA-DQ2 testing has no proven benefit for weight management. Many direct-to-consumer DNA tests overstate the predictive power of such variants for personalized diet plans. Weight loss is primarily driven by energy balance, diet quality, physical activity, and behavioral factors. While identifying celiac disease or gluten sensitivity may indirectly help some people, using HLA-DQ2 as a weight loss tool is not supported by evidence. The effect sizes are small, and the 'personalized diet' claims are largely marketing.