Reduced Carbohydrate Versus Fat in Obese Subjects

• Status: Completed
• Trial end date: 2014-10-20
• Target enrollment: 0
• Participant gender: All

Summary

Popular weight loss strategies often involve reducing an individual's consumption of carbohydrates or fat. However, no controlled study has been carried out to evaluate the effects of reducing carbohydrate versus fat consumption while keeping the other nutrients at standard levels to maintain an individual's weight. Researchers are interested in investigating how different restrictions of carbohydrates or fats affect the many processes involved in weight loss, including brain activity and blood and brain chemical composition.

• Phase: Phase 2
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
• Treatments: Fallypride

Criteria

• INCLUSION CRITERIA:

• Age 18-45 years, male or female

• Body mass less than 350 lbs. (max. weight dictated by table limit for functional magnetic resonance imaging (fMRI) scanner) when acquisition of large bore fMRI is complete, max. wt. limit will increase to 400 lbs.

• Weight stable (less than plus or minus 5 kg over past 6 months)

• Body mass index greater than or equal to 30.0 kg/m(2)

• Premenopausal (women only)

• Healthy, as determined by medical history and laboratory tests

• Able to complete daily bouts of walking at a moderate rate

• Written informed consent

EXCLUSION CRITERIA:

• Body mass greater than 350 lbs. (max. weight dictated by table limit for fMRI scanner) when acquisition of large bore fMRI is complete, max. wt. limit will increase to 400 lbs.

• BMI less than 30.0 kg/m(2)

• Evidence of metabolic or cardiovascular disease, or disease that may influence metabolism (e.g. cancer, diabetes, thyroid disease)

• Taking any prescription medication (except birth control) or other drug that may influence metabolism (e.g. diet/weight-loss medication)

• Hematocrit less than 34% (women only)

• Hematocrit less than 40% (men only)

• Pregnancy, lactation (women only)

• Allergy to lidocaine or ethanol

• Participating in a regular exercise program (greater than 2h/week of vigorous activity)

• Caffeine consumption greater than 150 mg/day (will be clamped at baseline intake during study)

• Regular use of alcohol (greater than 2 drinks per day), tobacco (smoking or chewing), amphetamines, cocaine, heroin, or marijuana over past 6 months

• Past or present history of eating disorder (including binge eating) or psychiatric disease

• Volunteers with strict dietary concerns (e.g. vegetarian or kosher diet, multiple food allergies)

• Are claustrophobic to a degree that they would feel uncomfortable in the MRI machine.

• Having any metal in their body (for example, pacemakers, metallic prostheses such as cochlear implants or heart valves, shrapnel fragments, etc.).

• Left-handedness

• Non-native English speakers

• Volunteers unwilling or unable to give informed consent

Control Subjects

INCLUSION CRITERIA:

• Age 18-45 years, male or female

• 18.5 kg/m(2) less than BMI less than 25.0 kg/m(2)

• Weight stable (less than plus or minus 5 kg over past 6 months)

• Premenopausal (women only)

• Healthy, as determined by medical history and laboratory tests

• Written informed consent

EXCLUSION CRITERIA:

• BMI less than 18.5 or greater than 25.0 kg/m(2)

• Evidence of metabolic or cardiovascular disease, or disease that may influence metabolism (e.g. cancer or diabetes)

• Taking any prescription medication (except birth control) or other drug that may influence metabolism (e.g. diet/weight-loss medication)

• Hyperlipidemia (fasting plasma triglyceride concentration greater than 150 mg/dl)

• Hematocrit less than 34% (women only)

• Hematocrit less than 40% (men only)

• Pregnancy, lactation (women only)

• Participating in a regular exercise program (greater than 2h/week of vigorous activity)

• Caffeine consumption greater than 150 mg/day

• Regular use of alcohol (greater than 2 drinks per day), tobacco (smoking or chewing), amphetamines, cocaine, heroin, or marijuana over the past 6 months

• Past or present history of eating disorder (including binge eating) or psychiatric disease

• Volunteers with strict dietary concerns (e.g vegetarian or kosher diet, multiple food allergies)

• Are claustrophobic to a degree that they would feel uncomfortable in the MRI machine.

• Having any metal in their body (for example, pacemakers, metallic prostheses such as cochlear implants or heart valves, shrapnel fragments, etc.).

• Left-handedness

• Non-native English speakers

• Volunteers unwilling or unable to give informed consent