Diet Order Effects of Low Fat vs. Low Carb Diets on Body Fat Change
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Summary
Background: In a previous study, participants were lived at the NIH and randomly received either a low-fat or a low-carbohydrate diet for 2 weeks and then switched to the other diet for 2 more weeks. Participants who received the low-carbohydrate diet first lost more body fat at the end of the study than those who received the low-fat diet first. Researchers want to see if they can repeat that result in a longer weight loss study when participants live at home. Objective: To test the effects of diet order in people receiving either a low-fat or low-carbohydrate diet first for 4 weeks and then immediately switched to the other diet for another 4 weeks. Eligibility: Adults aged 19 to 50 years with a body mass index of 25 or more. Design: Participants will complete the study at their homes, but there will be 3 required visits to the NIH. Participants will drink a special type of water 2 weeks before the baseline NIH visit and collect urine samples at home to measure how many calories they burn. Before the diets begin, participants will visit the NIH for baseline testing when they will have a metabolism test while relaxing in a bed with a plastic hood over their head to collect the air they breathe out. They will have scans to measure their bone density and how much muscle and body fat they have. They will give stool, blood, and urine samples. Participants will be asked to eat a specific diet for 4 weeks followed by a different diet for 4 weeks. All meals will be delivered to the participants' homes. They will eat only the foods delivered. Participants will weigh themselves daily. They will wear a monitor to track their physical activity and a sensor to measure their glucose levels. They will prick their finger each morning to test a drop of blood for ketones. Participants will meet virtually as a group with the study team weekly. Participants will have two more NIH visits towards the end of each diet period....
Description
Study Description: This is an 8-week crossover outpatient feeding trial of a low carbohydrate versus a low-fat diet, each provided for 4 weeks in random order with no washout period, in adult volunteers with overweight or obesity. Objectives: Primary Objectives: To determine the effect of diet order on the mean total fat mass change in subjects randomized to receive either a low carbohydrate followed by a low fat diet or the reverse order, with each diet lasting for 4 weeks. Secondary Objectives: To determine the effect of diet order on the mean rate of body weight change in subjects rando…
Eligibility
- Age range
- 18–50 years
- Sex
- All
- Healthy volunteers
- No
* INCLUSION CRITERIA: In order to be eligible to participate in this study, an individual must meet all of the following criteria: 1. Stated willingness to comply with all study procedures and availability for the duration of the study 2. Adults aged 18-50 years 3. Weight stable (\< +/- 5 percent over past 6 months) as determined by volunteer report 4. Body mass index (BMI) \>= 25 kg/m\^2 5. Agreement to adhere to Lifestyle Considerations throughout the study duration EXCLUSION CRITERIA: 1. Subjects with cardiac pacemakers or other implants that may be affected by or affect the DXA measure…
Interventions
- OtherLow-carbohydrate Diet
Consisting of 15 percent protein, 75 percent fat, and 10 percent carbohydrate
- OtherLow-fat Diet
Consisting of 15 percent protein, 10 percent fat, and 75 percent carbohydrate
Location
- National Institutes of Health Clinical CenterBethesda, Maryland