Early Time-Restricted Feeding Improves Insulin Sensitivity, Blood Pressure, and Oxidative Stress Even without Weight Loss in Men with Prediabetes.

Cell metabolism. 2018;27(6):1212-1221.e3

Plain language summary

Studies have shown that intermittent fasting (IF) can reduce body weight or body fat, as well as a number of metabolic markers. However, it is unknown whether the metabolic benefits are solely due to the weight loss. In addition, data from circadian studies suggest that eating earlier in the day has a positive effect on metabolism. The aim of this randomised, cross-over, controlled feeding trial was to evaluate the effects of early time-restricted feeding (eTRF) on weight and metabolic markers. eTRF was implemented as consuming all calories within a 6 hours window with the last meal no later than 3pm. 8 overweight men with prediabetes were randomized to either eTRF or a control schedule (12-hr feeding period) for 5 weeks, and later crossed over to the other schedule. During both eating regimes the same meals and calories were consumed in both groups in a controlled environment. eTRF improved insulin metabolism, blood pressure and oxidative stress, but not glucose levels, cholesterol or inflammatory markers. No weight loss occurred either during eTRF or control period, suggesting that the observed changes are independent of weight loss. The authors conclude that eTRF improves some aspects of cardiometabolic health and that these effects are not solely due to weight loss.

Abstract

Intermittent fasting (IF) improves cardiometabolic health; however, it is unknown whether these effects are due solely to weight loss. We conducted the first supervised controlled feeding trial to test whether IF has benefits independent of weight loss by feeding participants enough food to maintain their weight. Our proof-of-concept study also constitutes the first trial of early time-restricted feeding (eTRF), a form of IF that involves eating early in the day to be in alignment with circadian rhythms in metabolism. Men with prediabetes were randomized to eTRF (6-hr feeding period, with dinner before 3 p.m.) or a control schedule (12-hr feeding period) for 5 weeks and later crossed over to the other schedule. eTRF improved insulin sensitivity, β cell responsiveness, blood pressure, oxidative stress, and appetite. We demonstrate for the first time in humans that eTRF improves some aspects of cardiometabolic health and that IF's effects are not solely due to weight loss.

Lifestyle medicine

Fundamental Clinical Imbalances : Hormonal
Patient Centred Factors : Mediators/Fasting
Environmental Inputs : Diet
Personal Lifestyle Factors : Nutrition
Functional Laboratory Testing : Blood

Methodological quality

Jadad score : 2
Allocation concealment : Not applicable

Metadata