Effects of alternate-day fasting or daily calorie restriction on body composition, fat distribution, and circulating adipokines: Secondary analysis of a randomized controlled trial

Abstract

Background & aims: Indirect comparisons suggest that alternate-day fasting (ADF) may produce greater improvements in body composition, fat distribution, and/or the adipokine profile compared to daily calorie restriction (CR), but this has not been tested directly. In a pre-planned secondary analysis of a randomized controlled trial, we compared changes in the VAT:SAT ratio, FFM:total mass ratio, and the adipokine profile between ADF and CR.

Methods: Overweight and obese participants (n = 100) were randomized to 1) ADF (alternating every 24-h between consuming 25% or 125% of energy needs); 2) CR (consuming 75% of needs every day); or 3) control (consuming 100% of needs every day) for 24 wk.

Results: The VAT:SAT ratio did not change in any group. The FFM:total mass ratio increased in both ADF (0.03 ± 0.00) and CR (0.03 ± 0.01) compared to the control group (P < 0.01), with no differences between the intervention groups. Circulating leptin decreased in both the ADF group (-18 ± 6%) and CR group (-31 ± 10%) relative to the control group (P < 0.05), with no differences between the intervention groups. Circulating levels of adiponectin, resistin, IL-6, and TNF-α did not change in either intervention group relative to the control group.

Conclusion: ADF and CR similarly improve the FFM:total mass ratio and reduce leptin after a 24-wk intervention.

Trial registration: Clinicaltrials.gov, number NCT00960505.

Keywords: Adipokine; Alternate day fasting; Body composition; Calorie restriction; Obese adult; Visceral adipose tissue.

Conflict of interest statement

CONFLICT OF INTEREST

Krista Varady is the author of the book, “The Every Other Day Diet”, published by Hachette Book Group. The other authors declare no competing interests.

Copyright © 2017 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Figures

Figure 1

Study design. Participants maintained their usual diets during a 4-wk baseline run-in period to ensure body weight stability. They were then stratified by age, sex; and BMI; and randomly assigned to an ADF group, a CR group, or a non-intervention control group. Participants in the intervention groups received a controlled diet for the first 12 wk of intervention. They then self-selected their diets based on their individual daily calorie goals for the final 12 wk of intervention. Participants in the control group consumed their usual diet throughout the entire trial.

Figure 2

Changes in body composition and abdominal fat distribution. The figure shows the change in body composition (measured by DEXA; A) and abdominal fat distribution (measured by MRI; B) from baseline to week 24 (W24). Absolute values are depicted on the y-axis; and percentage values are depicted within the columns, which represent the relative amounts of (A) fat mass (FM) and fat-free mass (FFM) to total mass, and the relative amounts of (B) visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) to total abdominal mass. A, FM decreased in both intervention groups relative to the control group (P < 0.01 for all comparisons) with no differences between the intervention groups. FFM remained unchanged in all groups. The FFM:total mass ratio increased in both intervention groups compared to the control group (P < 0.01), with no differences between the intervention groups B, VAT decreased in both intervention groups relative to the control group (P < 0.05) with no difference between the intervention groups. SAT decreased in the calorie restriction (CR) group relative to the control group (P < 0.05) but did not change in the alternate day fasting (ADF) group relative to the other two groups. The VAT:SAT ratio did not change among the groups. Data are presented as mean ± SEM.

Figure 2

Changes in body composition and abdominal fat distribution. The figure shows the change in body composition (measured by DEXA; A) and abdominal fat distribution (measured by MRI; B) from baseline to week 24 (W24). Absolute values are depicted on the y-axis; and percentage values are depicted within the columns, which represent the relative amounts of (A) fat mass (FM) and fat-free mass (FFM) to total mass, and the relative amounts of (B) visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) to total abdominal mass. A, FM decreased in both intervention groups relative to the control group (P < 0.01 for all comparisons) with no differences between the intervention groups. FFM remained unchanged in all groups. The FFM:total mass ratio increased in both intervention groups compared to the control group (P < 0.01), with no differences between the intervention groups B, VAT decreased in both intervention groups relative to the control group (P < 0.05) with no difference between the intervention groups. SAT decreased in the calorie restriction (CR) group relative to the control group (P < 0.05) but did not change in the alternate day fasting (ADF) group relative to the other two groups. The VAT:SAT ratio did not change among the groups. Data are presented as mean ± SEM.