The Effect of 4:3 Intermittent Fasting on Weight Loss at 12 Months
Victoria A. Catenacci, Danielle M. Ostendorf, Zhaoxing Pan, Laura Grau, Seth A. Creasy, Adnin Zaman, Ann E. Caldwell, Jared H. Dahle, Bryan Swanson, Matthew J. Breit, Kristen Bing, Liza Wayland, Shelby L. Panter, Jared J. Scorsone, Daniel H. Bessesen, Paul S. MacLean, Edward L. Melanson
Abstract
BACKGROUND: Long-term (≥12 months) randomized trials evaluating the efficacy of intermittent fasting (IMF) as a dietary weight loss strategy are limited. Furthermore, no studies have compared IMF versus daily caloric restriction (DCR) when both interventions are provided in the context of a guidelines-based behavioral weight loss program. OBJECTIVE: To compare the effects of 4:3 IMF versus DCR on changes in weight at 12 months, with comprehensive behavioral support provided to both groups. DESIGN: Randomized clinical trial. (ClinicalTrials.gov: NCT03411356). SETTING: Denver, Colorado, and surrounding metropolitan area. PARTICIPANTS: . INTERVENTION: The IMF group was instructed to restrict energy intake by 80% on 3 nonconsecutive days per week, with ad libitum intake (no restriction) the other 4 days (4:3 IMF). The DCR group was instructed to reduce daily energy intake by 34% to match the weekly energy deficit of 4:3 IMF. Both groups received a high-intensity comprehensive behavioral weight loss program that included group-based behavioral support and a recommendation to increase moderate-intensity physical activity to 300 minutes per week. MEASUREMENTS: The primary outcome was change in body weight (in kilograms) at 12 months. RESULTS: = 0.040). LIMITATION: Limited generalizability. CONCLUSION: Compared with DCR, 4:3 IMF resulted in modestly greater weight loss among adults with overweight or obesity enrolled in a 12-month, high-intensity, comprehensive behavioral weight loss program. PRIMARY FUNDING SOURCE: National Institute of Diabetes and Digestive and Kidney Diseases.