Time Restricted Feeding (4-hour Versus 6-hour) for Weight Loss in Obese Adults
Condition: Obesity; Diabetes
MeSH terms: Weight Loss
Study type: Interventional

Summary: 
      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.
    

Detailed 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.
    

Intervention name(s): Time restricted feeding
Intervention type(s): Behavioral
Intervention description(s): TRF subjects will consume food ad libitum during the feeding window (4-h or 6-h window), and refrain from eating during the fasting window (20-h or 18-h window)
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Prevention