title: Adequacy of food rations in soldiers during an arctic exercise measured by doubly labeled water.
abstract: To investigate the adequacy of food rations to supply energy needs in cold-temperature environments, caloric expenditure and intake and body composition changes were measured in a group of infantrymen during a 10-day field exercise in the Canadian Arctic. Energy expenditure was measured by the doubly labeled water method (n = 10), and caloric intake was measured by complete food intake records (n = 20). Body composition was determined by isotope dilution (n = 10) and bioelectrical impedence analysis (n = 20) on days 0 and 10. Baseline isotopic enrichment shifts due to geographical relocation were also monitored (n = 5). Mean body weight decreased 0.63 +/- 0.83 (SD) kg over the study period (P < 0.005), although fat-free and fat mass compartment changes were not significant. Baseline isotopic changes were -4.65 +/- 2.54 and -0.48 +/- 0.07 /1000/day for deuterium and 18O, respectively. Mean baseline corrected energy expenditure level was 4,317 +/- 927 kcal/day. Self-reported caloric intakes obtained from food records were 2,633 +/- 499 kcal/day (61.0% of expenditure). Rations packs contained 4,350 kcal/day. Results suggest that 1) food intake was significantly underreported and 2) the energy needs of most subjects were being met by rations and available supplements.
authors.affiliation: Division of Human Nutrition, University of British Columbia, Vancouver, Canada.
authors.forename: P J
authors.initials: PJ
authors.lastname: Jones
authors.forename: I
authors.initials: I
authors.lastname: Jacobs
authors.forename: A
authors.initials: A
authors.lastname: Morris
authors.forename: M B
authors.initials: MB
authors.lastname: Ducharme
mesh_terms: D001110:Arctic Regions; D001823:Body Composition / Q000502:physiology; D001834:Body Water / Q000502:physiology; D017097:Electric Impedance; D002149:Energy Intake / Q000502:physiology; D004734:Energy Metabolism / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D005502:Food; D006801:Humans; D009751:Nutritional Requirements; D009752:Nutritional Status / Q000502:physiology*; D010104:Oxygen Radioisotopes
chemical_list: D010104:Oxygen Radioisotopes