The Childhood Shield: How Framework for Life-Course Pathway Analysis Using Mendelian Randomization Unravels the Causal Effects of Time-Varying Body Mass Index on Migraine

The causal effect of BMI on migraine is dependent on developmental timing, challenging the conventional view of BMI as a uniform risk factor. We emphasize that the observed protective role of childhood BMI is a model-estimated association from genetic data, which does not constitute a recommendation to increase body weight in children.