Extended Ketogenic Diet and Physical Training Intervention in Military Personnel

TLDR

Ketogenic diets that induce nutritional ketosis are being considered to address military readiness and obesity, yet evidence of their effects in service members is lacking. This study aimed to assess the feasibility, metabolic, and performance responses of an extended ketogenic diet with daily ketone monitoring in military personnel. Twenty‑nine healthy military adults underwent a 12‑week supervised training program, with 15 following an ad libitum ketogenic diet guided by daily capillary β‑hydroxybutyrate measurements and 14 maintaining a mixed diet, while pre‑ and post‑intervention tests measured body composition, insulin sensitivity, energy metabolism, and physical performance. Participants on the ketogenic diet achieved sustained nutritional ketosis, lost 7.7 kg body mass, reduced visceral fat by 43.7 %, improved insulin sensitivity by 48 %, and maintained comparable gains in aerobic capacity, strength, power, and obstacle‑course performance relative to the mixed‑diet group.

Abstract

Abstract Introduction Ketogenic diets (KDs) that elevate ketones into a range referred to as nutritional ketosis represent a possible nutrition approach to address the emerging physical readiness and obesity challenge in the military. An emerging body of evidence demonstrates broad-spectrum health benefits attributed to being in nutritional ketosis, but no studies have specifically explored the use of a KD in a military population using daily ketone monitoring to personalize the diet prescription. Materials and Methods To evaluate the feasibility, metabolic, and performance responses of an extended duration KD, healthy adults (n = 29) from various military branches participated in a supervised 12-wk exercise training program. Fifteen participants self-selected to an ad libitum KD guided by daily measures of capillary blood ketones and 14 continued their normal mixed diet (MD). A battery of tests were performed before and after the intervention to assess changes in body mass, body composition, visceral fat, liver fat, insulin sensitivity, resting energy metabolism, and physical performance. Results All KD subjects were in nutritional ketosis during the intervention as assessed by daily capillary beta-hydroxybutyrate (βHB) (mean βHB 1.2 mM reported 97% of all days) and showed higher rates of fat oxidation indicative of keto-adaptation. Despite no instruction regarding caloric intake, the KD group lost 7.7 kg body mass (range −3.5 to −13.6 kg), 5.1% whole-body percent fat (range −0.5 to −9.6%), 43.7% visceral fat (range 3.0 to −66.3%) (all p < 0.001), and had a 48% improvement in insulin sensitivity; there were no changes in the MD group. Adaptations in aerobic capacity, maximal strength, power, and military-specific obstacle course were similar between groups (p > 0.05). Conclusions US military personnel demonstrated high adherence to a KD and showed remarkable weight loss and improvements in body composition, including loss of visceral fat, without compromising physical performance adaptations to exercise training. Implementation of a KD represents a credible strategy to enhance overall health and readiness of military service members who could benefit from weight loss and improved body composition.