# Time Restricted Feeding as a Weight Loss Intervention in Overweight and Obese Adults

> **NIH NIH R21** · UNIVERSITY OF COLORADO DENVER · 2020 · $194,375

## Abstract

PROJECT SUMMARY
Obesity is a serious public health problem, and a majority of Americans are either overweight or obese.
Lifestyle modification, including reduction of energy intake (EI) and increase in energy expenditure (EE) are the
cornerstones in the treatment of obesity. Although caloric restriction is the most common dietary strategy used
to treat obesity, long-term adherence to caloric restriction is low and weight regain is common. Given the
limited success of current options in obesity treatment, there is a critical need for well-designed clinical trials of
alternative dietary approaches. Time restricted feeding (TRF) is one such strategy that may increase
adherence to caloric restriction and increase weight loss. Recent evidence suggests that a number of
metabolic systems are entrained to circadian rhythms, including hormone, lipid and glucose concentrations,
intestinal lipid absorption, and autonomic nervous system activity. Restriction of EI to a window of time and, by
necessity, the extension of the fasting period may alter diurnal patterns and circadian rhythms in glucose and
lipid metabolism in a manner that favors decreased obesity risk. The overall objective of this proposal is to
provide a foundation to inform the design of a future large-scale trial to evaluate the efficacy of TRF in
generating long-term weight loss. Our overall hypothesis is that a 12-month behavioral weight loss program
using TRF in the context of a reduced calorie diet (RCD+TRF) will produce greater weight loss as compared to
a behavioral weight loss program using a standard reduced calorie diet (RCD) without time restriction. In this
12-month pilot and feasibility study, 40 overweight and obese individuals will be randomized 1:1 to RCD+TRF
(10h self-selected feeding window ending no later than 4 hours prior to their usual bedtime) or a standard RCD
(no restriction on feeding duration). Measures include body weight and body composition, energy intake (EI),
physical activity (PA), glucose variability, sleep, compliance with caloric and time restriction, and
feasibility/acceptability. The specific aims are to: 1) Assess processes critical for the success of a large-scale
trial comparing the efficacy of RCD+TRF vs standard RCD on weight loss, EI, PA, sleep, and glucose
variability; 2) Assess the safety, tolerability, and acceptability of the RCD+TRF program; 3) Perform preliminary
efficacy testing and determine the variability of major outcome measures. Changes in weight, body
composition, PA, glucose variability and sleep will be compared between groups to provide preliminary efficacy
data and to obtain estimates of variability and effect size to assist with power and sample size calculations for
the future large-scale trial. We will also review program attendance, weight loss efficacy, and obtain participant
feedback on the RCD+TRF program. These data will be used to optimize the RCD+TRF program prior to the
future large-scale trial. Developing novel dietary a...

## Key facts

- **NIH application ID:** 9934190
- **Project number:** 5R21DK117499-02
- **Recipient organization:** UNIVERSITY OF COLORADO DENVER
- **Principal Investigator:** Marc-Andre Cornier
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $194,375
- **Award type:** 5
- **Project period:** 2019-06-01 → 2022-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9934190

## Citation

> US National Institutes of Health, RePORTER application 9934190, Time Restricted Feeding as a Weight Loss Intervention in Overweight and Obese Adults (5R21DK117499-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9934190. Licensed CC0.

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