The goal of this randomized controlled trial is to test the effect of time-restricted eating (14-hour fast, 10-hour eating window) of a low-energy dense diet (reduced calories per gram of food) in older adults with obesity and insulin resistance. The study aims to determine if modulating the energy density of the diet reduces: 1. Insulin resistance and 2. Body weight. Researchers will compare the groups: 1. Following time-restricted eating and given a diet reduced in energy density or 2. Following time-restricted eating and given a diet typically consumed in this population