Environment, lifestyle, diet, marketing, and biology are all contributors to the obesity epidemic.  How do our bodies balance the storage and burning of dietary fat? Fat carries information about how it should be used. Saturated fats are hard to break down, so they tend to get stored, while unsaturated fats are more readily consumed for energy. Too much stored fat leads to elevated blood glucose levels, which triggers insulin resistance — the first step toward diabetes. Dr. Evans explores how diet and exercise influence the relationship between fat and muscle, promoting good health or precipitating diseases such as syndrome X, a disorder involving high blood pressure, heart disease, atherosclerosis, and insulin resistance. From the Series:HHMI’s Understanding Biomedical Research Series