In the CALERIE 2 randomized clinical trial, Martin and colleagues tested the effect of 2 years of calorie restriction (CR) on mood, quality of life (QOL), sleep, and sexual function in healthy nonobese adults. Healthy adult men and women with a body mass index (calculated as weight in kilograms divided by height in meters squared) between 22 and 28 were enrolled and assigned to 2 years of 25% CR or an ad libitum control group. Self-report questionnaires were used to measure mood, QOL, sleep, and sexual function at baseline, 12 months, and 24 months. The CR group and ad libitum control group both lost weight at month 24, but the CR participants reported reduced tension and improved mood, general health, sexual drive, and sleep. Also, greater weight loss among the CR participants was associated with improvements in health-related QOL.