A University of Toronto study using data from thousands of Canadian children found that kids drinking whole milk at age 5 had 69% lower odds of obesity by age 8 compared to those drinking skim milk, contradicting decades of dietary guidance promoting low-fat dairy. The research, published in the American Journal of Clinical Nutrition, suggests milk fat may improve satiety and metabolic function rather than increasing obesity risk. The finding aligns with recent U.S. policy shifts — the 2026 Whole Milk for Healthy Kids Act now allows full-fat milk in school lunches — though researchers note the mechanisms are not yet fully understood and long-term effects into adolescence and adulthood remain unknown.