By Dr. Liji Thomas, MD Reviewed by Lauren Hardaker Apr 15 2026 Weight gained in your 20s may matter more than later in life, with new evidence showing that early adult weight trajectories could shape your risk of dying from heart disease, cancer, and other chronic conditions decades later. Study: Weight trajectories and obesity onset between 17 and 60 years of age, and cause-specific mortality: the Obesity and Disease Development Sweden (ODDS) pooled cohort study . Image credit: Flotsam/