Extended Ketogenic Diet and Physical Training Intervention in Military Personnel

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.

Effects of a ketogenic diet on body composition and strength in trained women

“…Kephart et al also found no negative results on the 1RM back squat when compared to a NKD group. Recently, it has been reported similar changes on anaerobic parameters related to lower and upper-limb strength and power between a KD and NKD groups [42]. In fact, our study also showed similar increases on power (CMJ) after the dietary interventions in both groups from baseline.…”

“…The nutritional intervention of this study did not consider specific values of total calories or macronutrients used per g•kg − 1 •d − 1 , impairing the ability to estimate whether participants were in a state of energy deficiency or surplus. Similarly, recent research on male military personnel have shown a reduction on BM (including FFM loss) in the KD group only, while the NKD group increased this parameter with a significant reduction in FM; notwithstanding, energy intake was not controlled in this study [42]. In contrast, Volek et al [43] reported a statistically significant increase in FFM (1.1 kg) in moderately active male participants, some of whom reported routinely performing moderate intensity RT, following a 6-week RT program.…”

Carbohydrate Restriction in Type 1 Diabetes: A Realistic Therapy for Improved Glycaemic Control and Athletic Performance?

“…Nonetheless, individuals with T1D often make claims in various social media forums and in some self-report surveys (see below) that they can still be physically active and train while adhering to a LCD. Interestingly, LaFountain and colleagues [39] found that a 12-week VLCD (≤50 g carbohydrate per day) did not compromise physical performance compared to a mixed diet in military personnel without T1D. The study also demonstrated improved insulin sensitivity and body composition following the VLCD alongside high adherence.…”

Investigating Ketone Bodies as Immunometabolic Countermeasures against Respiratory Viral Infections

“…69 Endogenous and exogenous ketones have been demonstrated to reduce acute and/or chronic markers of glycemic load in healthy and diabetic populations. 41,49,[70][71][72][73] We hypothesize that consumption of exogenous ketones may improve specific clinical outcomes of respiratory viral infection through already-understood molecular mechanisms. Older patients and patients with diabetes, in whom these mechanisms are most relevant, may be the groups most likely to benefit from exogenous ketone body administration.…”

“…69 Endogenous and exogenous ketones have been demonstrated to reduce acute and/or chronic markers of glycemic load in healthy and diabetic populations. 41 , 49 , 70 , 71 , 72 , 73 …”