A large genetic analysis lends credence to the idea that insulin spikes after eating high-glycemic foods promote weight gain. People genetically predisposed to produce higher than normal levels of insulin after eating processed carbohydrates — “bad carbs” like white bread, potatoes and refined sugar — were more likely to be obese, the study found.

The researchers, led by David Ludwig, MD, PhD, of Boston Children’s Hospital, Joel Hirschhorn, MD, PhD, of Boston Children’s and the Broad Institute, and Jose Florez, MD, PhD, of the Broad Institute and Massachusetts General Hospital, tapped a collection of large-scale genome-wide association studies. Analyzing data from more than 26,000 people who had glucose challenges, they identified genetic variants linked with high insulin levels 30 minutes after the challenge. …