Effects of Overnight Low Oxygen Exposure on Energy Balance

Eligibility Details: Inclusion Criteria: - Men and women aged 20 - 45 years - Body mass index between 18.5 - 24.5 kg/m2 - Born at altitudes less than 2,100 meters (~7,000 feet) - Currently residing in Tallahassee, Florida or the surrounding area - Not taking any medication(s) that interfere with metabolism or oxygen delivery/transport for four weeks before and throughout the entire study (e.g., includes sedatives, sleeping aids, tranquilizers, and/or any medication that depresses ventilation, diuretics, alpha, and beta-blockers). - Willing to refrain from smoking, vaping, chewing tobacco, and dietary supplement use throughout the entire study - Willing to spend two overnight visits on the Florida State University campus. Exclusion Criteria: - Living in areas that are more than 1,200 m (~4,000 feet), or have traveled to areas that are more than 1,200 m for five days or more within the last two months - Metabolic or cardiovascular abnormalities, gastrointestinal disorders, or any condition that interferes with metabolism or oxygen delivery/transport (e.g., kidney disease, diabetes, cardiovascular disease, etc.) - Prior diagnosis of apnea or other sleeping disorders - Prior diagnosis of high-altitude pulmonary edema or high-altitude cerebral edema - Prior diagnosis of anemia or sickle cell anemia/trait - Present condition of alcoholism, anabolic steroid, or other substance abuse issues - Women who are pregnant, lactating, planning to become pregnant, or who have had an irregular menstrual cycle in the past six months. - Allergies or intolerance to foods included in the standardized or ad libitum meal (e.g., lactose intolerance/milk allergy)