Iron Absorption in The Low Oxygen Exposure and Weight Status (LOWS) Study

Inclusion Criteria:

* Obese (BMI between 30-39.9 kg/m2)
* Born at altitudes below 2,100 meters (\~7,000 feet)
* Currently residing in Baton Rouge, Louisiana or surrounding area
* Not taking any medication(s) that interfere with oxygen delivery/transport for 4 weeks prior to 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 have a hypoxic tent set-up in their home and spend 8 consecutive hours per night in the tent for 8 weeks

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 2 months
* Cardiovascular abnormalities, gastrointestinal disorders, or any condition that interferes with oxygen delivery/transport (e.g., kidney disease, cardiovascular disease, etc.)
* Oxygen saturation \< 95% while awake or oxygen saturation dips below 88% for a total of ≥ 10 min overnight in normoxic conditions
* Evidence of apnea or other sleeping disorders
* Evidence of prior high-altitude pulmonary edema (HAPE) or high-altitude cerebral edema (HACE) diagnosis
* Diagnosis or family history of sickle cell anemia/trait
* Hematocrit \<42% for males, \<36% for females
* Hemoglobin \<13 g/dL for males, \<12 g/dL for females
* Blood donation within 8 weeks of beginning the study
* Present condition of alcoholism, anabolic steroids, 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 6 mo.
* Weight gain or loss \> 10% of body weight during the past 6 months
* Adults unable to consent