Military Health and Nutrition Examination Study

24-hour dietary recalls will be collected using ASA24® to measure intake of macronutrients (protein, carbohydrate, and fat) and micronutrients (vitamins and minerals).

24-hour dietary recalls will be collected using ASA24®. Diet quality will be assessed by the healthy eating index (HEI).

Depression will be assessed by the Patient Health Questionnaire-9 (PHQ-9).

Anxiety will be assessed by the General Anxiety Disorder-7 (GAD-7) questionnaire.

Resilience will be assessed by the Connor-Davidson Resilience Scale (CD-RISC).

Posttraumatic stress disorder (PTSD) will be assessed by the the Primary Care PTSD Screen for DSM-5 (PC-PTSD-5).

Self-efficacy will be assessed by the Generalized Self-Efficacy Scale (GSE).

Mood state will be assessed by the Profile of Mood States 2 (POMS2) questionnaire.

Physical activity will be measured using the ActiGraph wGT3X-BT wearable device.

Physical activity will be assessed by the Physical Activity and Physical Fitness Questionnaire from NHANES.

Participants will self-report their most recent Army Combat Fitness Test (ACFT) results.

A questionnaire on orthopedic injuries will be administered.

Sleep duration and quality will be measured using the ActiGraph wGT3X-BT wearable device.

Sleep duration and quality will be assessed by using the Pittsburgh Sleep Quality Index (PSQI).

Assessed using the Satiety scale derived from the validated Military Eating Behavior Survey (MEBS)

Assessed using the Fast Eating Rate scale derived from the validated Military Eating Behavior Survey (MEBS)

Assessed using the Slow Eating Rate scale derived from the validated Military Eating Behavior Survey (MEBS)

Measured after an overnight (at least 10 hour) fast, blood pressure will be measured with an automated cuff.

Height measured using a stadiometer. Body mass and composition (fat mass, percent fat, fat-free mass, skeletal muscle mass, and body water) using bioelectrical impedance analysis, body image scanning, and neck, waist, and hip circumference measurements. If available, at 1-2 Army bases, dual x-ray absorptiometry (DXA) will be used.

Measured in blood

Measured in urine

Measured in stool

Volunteers will be asked the name of each supplement and medication used in the past 30 days and the dose, unit, frequency, route, indication, and start/stop date. An opaque bag will be provided to volunteers to transport supplements to the in-person visit. Dietary supplement use will also be assessed by ASA24® in conjunction with the 24-hour dietary recall.

Measured by indirect calorimetry (MedGem or BodyGem indirect calorimeter).

Heart rate variations will be continuously recorded for 10 minutes with the Zephyr Bioharness™ (Zephyr Technology Corporation, Annapolis, MD, US).

Array-based genotyping using blood samples

Hemoglobin mass (Hbmass) will be determined in a subset of participants using the automated CO-rebreathing method. The method is based on the dilution principle where a small volume of tracer (CO) is administered and the subsequent concentration of carboxyhemoglobin (COHb) in the blood allows for calculation of Hbmass.

Total daily energy expenditure will be assessed by the Doubly Labeled Water (DLW) method. Prior to dosing, volunteers will provide a urine sample that will be used to measure background isotope enrichment. Urine will be collected at 4.5 h and 7 d after dosing. Isotopic elimination rates will be calculated to get the rate of CO2 production. Energy expenditure will be calculated by multiplying the rate of CO2 production by an assumed food quotient of the diet.

This is a 5-min test of simple visual reaction time widely used to assess alertness. The test requires volunteers to sustain attention and respond to stimuli presented at random intervals on a computer screen by pressing a button. Parameters recorded include reaction time, premature responses, correct responses, and number of lapses.