Background: A lifestyle characterized by poor eating habits and physical inactivity is a risk factor for multiple lifestyle diseases in young adults. This study assessed the effects of implementing an intensive 10-day health promotion program combining diet and physical activities on body composition, physical fitness, and biochemical parameters of young adults. Material/Methods: In this randomized pilot study, 30 female undergraduate students were randomly allocated to an intervention and a control group. The health promotion program consisted of unlimited amounts of vegetarian food; aerobic, flexibility, and strength exercises (3 hours/day); lectures on health (3 hours/day); massage practice (2 hours/day); and healthy cooking practice (1 hour/day). The effects of the intervention were analyzed using the Mann-Whitney U test and the Wilcoxon signed-rank test. Results: The intensive 10-day health promotion program significantly reduced body weight, body mass index, triglyceride, total cholesterol, low-density lipoprotein cholesterol, blood glucose, and the homeostasis model assessment of insulin resistance. At the same time, participants demonstrated increased back muscle, leg muscle, and grip strength; waist and shoulder flexibility; balance; and cardiorespiratory endurance. Conclusions: The intensive 10-day health promotion program is a viable intervention for improving body composition, physical fitness, glycemic control, and blood lipid levels in young adults.