Abstract
BACKGROUND: Diet and exercise are the cornerstone of obesity prevention and treatment. However, a substantial number of individuals are non-responsive to existing weight-loss interventions and obesity rates continue to rise. Daily exposure to low-oxygen conditions may aid in current weight-loss strategies by increasing resting metabolic rate and decreasing appetite. Whether in-home, overnight, normobaric hypoxic exposure promotes body weight loss in adults with obesity remains unknown. METHODS: Fifty adults with obesity (BMI: 30-39.9 kg/m(2)) will complete this double-blind, parallel-arm, randomized, controlled-feeding clinical trial. Participants will be provided with a weight maintenance diet for 2 weeks while undergoing baseline measurements. Following the weight maintenance phase, an energy restricted diet (500 kcal/day below weight maintenance needs) will be provided in combination with either overnight exposure to normobaric hypoxia (8 h/night, 15% oxygen, elevation ∼2,640 m) or normoxia (8 h/night, 21% oxygen, elevation ∼60 m), using a commercially available, in-home tent system, for 8 weeks. The primary outcome is the difference in body weight change between interventions. Secondary outcomes include measures of body composition, total and resting energy expenditure, energy intake from an ad libitum meal, insulin sensitivity and glycemic control, sympathetic tone, iron absorption and indicators of iron status, stool microbial diversity and composition, appetite, psychosocial factors, and sleep quantity and quality. DISCUSSION: Chronic, overnight, low oxygen exposure may provide a novel intervention to supplement current weight-loss strategies, inform new strategies to accelerate weight loss, and aid long-term weight management efforts in adults with obesity. CLINICAL TRIAL REGISTRATION: Clinicaltrials.govNCT05289310.