Effect of Time-based Energy Intake Goals on Weight Loss During Obesity Treatment
The University of Tennessee, Knoxville
Summary
The goal of this randomized controlled trial is to learn how the time of day when calories are eaten affects weight loss in the long-term (12 months). The main aims are to learn: 1. The influence of time-based energy intake goals on longer-term weight loss. 2. The influence of time-based energy intake goals on eating temporal patterns, sleep regularity, and appetite regulation. Researchers will compare whether goals to eat most of a person's calories in the morning or evening work to treat obesity. Participants will: 1. Eat a reduced-calorie, low-fat diet (some participants will have goals to eat their calories at certain times of day based on their group) 2. Be physically active at least 200 minutes 3. Receive a cognitive behavioral intervention
Description
This randomized controlled trial investigates the longer-term (12 months) effect of time-based energy intake goals on weight loss. It also explores whether enhanced appetite regulation is a mediator of the relationship and if chronotype moderates the effect. Adults with overweight or obesity are randomly assigned to one of three, 12-month lifestyle interventions: 1) Morning; 2) Evening; or 3) Standard. All conditions receive a reduced-energy, low-fat dietary prescription (1200-1500 kcal/d, \< 30% energy from fat), physical activity goals (\> 200 min/wk of moderate- to vigorous-intensity physic…
Eligibility
- Age range
- 25–60 years
- Sex
- All
- Healthy volunteers
- No
Inclusion Criteria: * Body mass index (BMI) between 27 and 45 kg/m2. Exclusion Criteria: * Report not regularly (\>/= 5 days/wk) consuming energy (\>/= 100 kcal) prior to 12 pm, and not being able to consume energy every day (\>/= 50 kcal) within one hour of awakening. * Report taking sleep medication or not regularly (\>/= 5 nights/wk) getting at least 6 hrs of total sleep. * Report being a shift workers/alternative shift workers that work outside of 7 am and 7 pm. * Report being diagnosed with type 1, or type 2 diabetes and taking medication that requires eating to occur at certain time p…
Interventions
- BehavioralDEPTH
All conditions will receive a reduced-energy, low-fat dietary prescription (1200-1500 kcal/d, \< 30% energy from fat), physical activity goals (\> 200 min/wk of moderate- to vigorous-intensity physical activity \[MVPA\]) and a cognitive behavioral intervention. To minimize the effect of other eating temporal variables on outcomes, guidance on the eating window length and the number of eating occasions in the day will be consistent across all three conditions. Thus, the three conditions will be instructed to have their first eating occasion \< 60 minutes of awakening, and eat their three meals and one snack within a 12-hr eating window.
- BehavioralDEPTH-Morning
Morning will also have time-based energy intake goals of 70% of kcal within the first 6 hrs of the eating window and 30% of kcal within the last 6 hrs of the eating window (a morning-loaded energy distribution).
- BehavioralDEPTH-Evening
Evening will also have time-based energy intake goals of 30% of kcal within the first 6 hrs of the eating window and 70% of kcal within the last 6 hrs of the eating window (an evening-loaded energy distribution).
Location
- Healthy Eating and Activity LaboratoryKnoxville, Tennessee