Related Experiment Video
Updated: Jun 12, 2025
Assessment of the Metabolic Effects of Isocaloric 2:1 Intermittent Fasting in Mice
Published on: November 27, 2019
The Effect of 4:3 Intermittent Fasting on Weight Loss at 12 Months : A Randomized Clinical Trial
Victoria A Catenacci1, Danielle M Ostendorf2, Zhaoxing Pan3
1Anschutz Health and Wellness Center, University of Colorado, School of Medicine, Anschutz Medical Campus, and Division of Endocrinology, Metabolism, and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado (V.A.C., S.A.C., A.E.C., K.B., L.T.W., D.H.B.).
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:
Adults aged 18 to 60 years with body mass index (BMI) of 27 to 46 kg/m2.
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:
Of the 165 (4:3 IMF, n = 84; DCR, n = 81) randomly assigned participants (mean age, 42 years [SD, 9]; mean BMI, 34.1 kg/m2 [SD, 4.4]; 73.9% female), 125 completed the trial. In an intention-to-treat analysis, 4:3 IMF showed greater reductions in weight than DCR at 12 months (mean difference, 2.89 kg [95% CI, 5.65 to 0.14 kg]; P = 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.
More Related Videos
06:28A Chronic High-Intensity Interval Training and Diet-Induced Obesity Model to Maximize Exercise Effort and Induce Physiologic Changes in Rats
Published on: April 28, 2023
06:13Author Spotlight: Exploring the Impact of Reduced Resistance Exercise Volume on Metabolic Health
Published on: December 1, 2023
