Diet-related Behaviors Are Associated with Energy Intake and Body Weight Loss During a Sustained Military Training Exercise (P16-012-19)

Abstract

ObjectivesSustained negative energy balance during military operations contributes to degradations in physical and cognitive performance. Characterizing the diet-related behaviors and nutrition knowledge of Soldiers who self-select higher energy intakes during military operations may identify strategies for promoting energy balance. This study aimed to identify diet-related behaviors of Soldiers who self-selected higher energy intakes during a simulated military operation. MethodsDietary intake and body weight were measured daily in 54 Soldiers (91% male, BMI 25 ± 4 kg/m2, 25 ± 4 yr) participating in a 3-d military exercise. During the exercise, Soldiers were provided with military rations (2787–3003 kcal/d), and in some cases consumed items from home or mobile catering. Food frequency and nutrition knowledge questionnaires were completed before the exercise to assess diet quality by HEI-2010 total score and nutrition knowledge, respectively, and questionnaires assessing eating behaviors during the exercise were completed daily and after the exercise. Associations between diet quality, nutrition knowledge, and diet-related behaviors with 1) daily energy intake (EI) and 2) weight loss (∆BW) were determined by backwards elimination multiple linear regression. ResultsEI (mean ± SD: 1947 ± 627 kcal/d) and ∆BW (−1.4 ± 1.2%) during the exercise were not correlated. After adjusting for baseline BMI, EI was associated with diet quality (β ± SE: 17 ±9 kcal/d, P = 0.07) and eating frequency (170 ± 86 kcal/d, P = 0.06) and more often intentionally eating foods to improve performance (−389 ± 207 kcal/d, P = 0.07) during the exercise (R2 = 0.27, P = 0.03). In contrast, greater ∆BW was associated only with more often “not allowing myself to eat” certain foods during the exercise (R2 = 0.11; −0.8 ± 0.4%, P = 0.04). Nutrition knowledge was not a significant predictor in either model. ConclusionsFindings suggest that self-selected energy intake and body weight loss during military operations may be associated with habitual adherence to healthier dietary patterns and conscious decisions regarding what and how often to eat and/or drink during operations, but not with general nutrition knowledge. Funding SourcesU.S. Army Medical Research & Materiel Command; US Army Natick Research, Development, & Engineering Center. Disclaimer: Authors’ views do not reflect official DoD policy.