Four Weeks of Time-Restricted Feeding Combined with Resistance Training Does Not Differentially Influence Measures of Body Composition, Muscle Performance, Resting Energy Expenditure, and Blood Biomarkers.

Matthew T Stratton,Gerald T Mangine,Garrett M Hester,Alex A Olmos,Paul R Serafini,Michaela G Alesi,Austin T Webb,Andrew S Modjeski,Kelsey King,Trisha A Vandusseldorp,Grant M Tinsley,Shelby N Savage

doi:10.3390/nu12041126

Abstract

Recently, interest in time-restricted feeding (TRF) has increased from reports highlighting improvements in body composition and muscular performance measures. Twenty-six recreationally active males were randomly assigned to either TRF (n = 13; ~22.9 years; 82.0 kg; 178.1 cm; 8 h eating window, 25% caloric deficit, 1.8 g/kg/day protein) or normal diet (ND; n = 13; ~22.5 years; 83.3 kg; 177.5 cm; normal meal pattern; 25% caloric deficit, 1.8 g/kg/day protein) groups. Participants underwent 4-weeks of supervised full body resistance training. Changes in body composition (fat mass (FM), fat free mass (FFM), and body fat percentage (BF%)), skeletal muscle cross sectional area (CSA) and muscle thickness (MT) of the vastus lateralis (VL), rectus femoris, (RF), and biceps brachii (BB) muscles, resting energy expenditure (REE), muscular performance, blood biomarkers, and psychometric parameters were assessed. Significant (p < 0.05) decreases were noted in BM, FM, BF%, testosterone, adiponectin, and REE, along with significant increases in BP1RM, LP1RM, VJHT, VJPP, VLCSA, BBCSA, and BBMT in both groups. Plasma cortisol levels were significantly elevated at post (p = 0.018) only in ND. Additionally, FFM was maintained equally between groups. Thus, a TRF style of eating does not enhance reductions in FM over caloric restriction alone during a 4-week hypocaloric diet.

Highlights

Fasting can be defined as abstinence from ingesting food and caloric beverages for specified time periods, ranging from hours to several weeks [1,2]
One individual was excluded for lack of adherence to the fasting protocol (TRF group), and three were excluded (TRF: 1, normal diet (ND): 2) for lack of dietary adherence via dietary logs collected throughout the study
The independent samples t-tests demonstrated no significant differences between groups for baseline values of all dependent variables (Table 1)

Summary

Introduction

Fasting can be defined as abstinence from ingesting food and caloric beverages for specified time periods, ranging from hours to several weeks [1,2]. While previous investigations have examined the potential impact of IF on body composition [9,11,12,13,14,15,16] and metabolic health markers [9,13,14,17,18], the majority of investigations have been carried out in overweight and obese populations and without the implementation of a structured exercise program [12,13,14,15,16,17,19,20] These investigations have primarily employed either ADF or mADF styles of fasting, as opposed to the more commonly practiced TRF

Objectives

Methods

Results

Discussion

Conclusion