Weight Loss Greater With Intermittent Fasting Than Calorie Restriction

MONDAY, March 31, 2025 (HealthDay News) — An intermittent fasting (IMF) intervention yields modestly greater weight loss than daily caloric restriction (DCR) among adults with overweight or obesity, according to a study published online April 1 in the Annals of Internal Medicine.

Victoria A. Catenacci, M.D., from the University of Colorado Anschutz Medical Campus in Aurora, and colleagues compared the effects of 4:3 IMF versus DCR on changes in weight at 12 months with comprehensive behavioral support in a randomized clinical trial involving adults aged 18 to 60 years with a body mass index of 27 to 46 kg/m². The IMF group was instructed to restrict energy intake by 80 percent on three nonconsecutive days per week, with no restriction on the other four days (4:3 IMF). The DCR group was instructed to match the weekly energy deficit by reducing daily energy intake by 34 percent. Both groups also received a high-intensity comprehensive behavioral weight loss program.

The study included 165 participants: 84 4:3 IMF and 81 DCR; 125 individuals completed the trial. The researchers found that at 12 months, 4:3 IMF showed greater reductions in weight than DCR in an intention-to-treat analysis (mean difference, 2.89 kg).

“4:3 IMF should be considered within the range of evidence-based dietary weight loss approaches,” the authors write.

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