Time Restricted Feeding (4-hour Versus 6-hour) for Weight Loss in Obese Adults

University of Illinois

Status: Completed

Conditions: Diabetes; Obesity

Treatments: Behavioral: Time restricted feeding

Study type: Interventional

Funder types: Other

Identifiers

NCT03867773

2018-1525

Details and patient eligibility

About

The aims of this proposal are to compare the effects of 4-h versus 6-h time restricted feeding (TRF) on body weight and metabolic disease risk factors in adults with obesity. To test the study objectives, a 10-week randomized, controlled, parallel-arm trial, divided into 2 consecutive periods: (1) 2-week baseline period; and (2) 8-week TRF weight loss period, will be implemented. Obese subjects will be randomized to 1 of 3 groups: (1) 4-h TRF, (2) 6-h TRF, or a no-intervention control group. This study will be the first randomized controlled trial to compare 4-h versus 6-h TRF.

Full description

Modest weight loss of 5-10% is sufficient to reduce metabolic disease risk in obese individuals. The first line of therapy prescribed for weight loss is daily calorie restriction (CR; 25% restriction every day). However, adherence to CR greatly diminishes after 4-6 weeks, due to subject frustration with constantly having to count calories and never being able to eat freely. In light of these issues with CR, another approach that limits timing of food intake, instead of number of calories consumed, has been developed. This strategy is termed time restricted feeding (TRF), and involves confining the period of food intake to 8 h/d (10 am to 6 pm) without calorie counting. Preliminary findings of 8-h TRF demonstrate modest weight loss and blood pressure reductions after 12 weeks. What remains unknown however, is whether shorter feeding windows during TRF (such as 4-h or 6-h feeding windows) can produce even greater weight loss in obese adults. Also of interest, is the impact of these shorter feeding windows on metabolic disease risk indicators (such as plasma lipids, blood pressure, and insulin resistance, inflammation and oxidative stress). Accordingly, the aims of this proposal are: AIM 1: To compare the effects of 4-h versus 6-h time restricted feeding (TRF) on body weight in adults with obesity; AIM 2: To compare the effects of 4-h versus 6-h TRF on metabolic disease risk factors in adults with obesity. To test the study objectives, a 10-week randomized, controlled, parallel-arm trial, divided into 2 consecutive periods: (1) 2-week baseline period; and (2) 8-week TRF weight loss period, will be implemented. Obese subjects will be randomized to 1 of 3 groups: (1) 4-h TRF, (2) 6-h TRF, or a no-intervention control group. This study will be the first randomized controlled trial to compare 4-h versus 6-h TRF on body weight and metabolic disease risk markers.

Enrollment: 82 patients

Sex: All

Ages: 18 to 65 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Male or female;
• body mass index (BMI) between 30.0 and 49.9 kg/m2;
• age between 18 and 65 years; sedentary (light exercise less than 1 h per week) or moderately active (moderate exercise 1 to 2 h per week);
• weight stable for >3 months prior to the beginning of the study (gain or loss <4 kg);
• able to give written informed consent

Exclusion criteria

• Smoker; diabetic;
• taking weight loss medications;
• taking medication that requires eating food before (or with) the medication; history of eating disorders;
• night-shift workers;
• perimenopausal;
• pregnant women

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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82 participants in 3 patient groups

4-hour Time restricted feeding

Experimental group

Description:

4-h TRF subjects will consume food ad libitum between 3pm and 7pm (4-h feeding window), and refrain from eating and drinking caloric beverages from 7pm to 3pm (20-h fasting window) each day. These subjects will not be instructed to limit/monitor energy intake during the feeding window. Subjects will be encouraged to drink plenty of water during the fasting period.

Treatment:

Behavioral: Time restricted feeding

Control

No Intervention group

Description:

Controls will be instructed to maintain their weight throughout the trial, and not to change eating or physical activity habits. Controls will visit the research center at the same frequency as the TRF groups (for outcome measurements).

6-hour Time restricted feeding

Experimental group

Description:

6-h TRF subjects will consume food ad libitum between 1pm and 7pm (6-h feeding window), and refrain from eating and drinking caloric beverages from 7pm to 1pm (18-h fasting window) each day. These subjects will not be instructed to limit/monitor energy intake during the feeding window. Subjects will be encouraged to drink plenty of water during the fasting period.

Treatment:

Behavioral: Time restricted feeding