The goal of this randomized controlled trial is to learn how the time of day when calories are eaten affects weight loss in the long-term (12 months). The main aims are to learn: 1. The influence of time-based energy intake goals on longer-term weight loss. 2. The influence of time-based energy intake goals on eating temporal patterns, sleep regularity, and appetite regulation. Researchers will compare whether goals to eat most of a person's calories in the morning or evening work to treat obesity. Participants will: 1. Eat a reduced-calorie, low-fat diet (some participants will have goals to eat their calories at certain times of day based on their group) 2. Be physically active at least 200 minutes 3. Receive a cognitive behavioral intervention