Experimental Approach to Test Predictions of Body Weight Regulation Models
Pennington Biomedical Research Center
Summary
The regulation of human body weight and fatness is not fully understood. Although some models of regulation have been proposed (set point, dual-intervention point, others), no studies have been designed to test their predictions. In this pilot and feasibility study, the investigators will implement an experimental approach to test the predictions of models of body weight regulation in humans. Men and women with either low body weight or obesity will be exposed to a 2-day fasting followed by a 2-day ad-libitum refeeding. During the entire fasting-refeeding period, energy intake and expenditure will be accurately measured within metabolic chambers. The investigators will therefore determine the compensatory responses to fasting elicited to prevent weight loss. The results will serve to design and power future studies to better understand body weight regulation.
Description
Background: Although body weight regulation models have been proposed, experimental approaches for testing their predictions are lacking. The set point (SP) model proposes that a biologically determined fatness is defended by activating compensatory responses to prevent its change. The dual-intervention point (DIP) model proposes that there are two levels of fatness (lower and upper intervention points) within which fatness is weakly regulated. Compensatory responses would only be activated once the lower or upper intervention points are reached. In response to prolonged fasting, the SP model…
Eligibility
- Age range
- 18–40 years
- Sex
- All
- Healthy volunteers
- Yes
Inclusion Criteria: * Body mass index lower than 20 kg/m2 for the low body weight group, or 30 kg/m2 or greater for the obesity group * 18-40 years old * Nulliparous and regular menstrual cycle (25-35 days) during the last six months (in women) * Normal thyroid function, blood count, and chemistry 15 panel (normal plasma glucose will be considered at \<100 mg/dL; normal serum HDL cholesterol at \>=50 mg/dL for women and \>=40 mg/dL for men; and normal serum triglycerides at \<150 mg/dL). * Self-reported weight stability during the last six months (±3 kg) * Rate the liking of at least one of t…
Interventions
- BehavioralFasting-refeeding cycle
Participants will be maintained in metabolic chambers and exposed to 1 day of energy balance with a standard diet, 2 days of fasting (only water), and 2 days of ad-libitum refeeding using a liquid diet provided in hydration bladders to avoid portion control.
Location
- Pennington Biomedical Research CenterBaton Rouge, Louisiana