J. Philip Karl

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Eating rate has recently been shown to influence energy intake and appetite during an ad libitum meal, and alter postprandial secretion of glucagon-like peptide-1 (GLP-1) and peptide-YY (PYY) following a fixed-portion meal. Whether these effects influence satiety, as measured by energy intake at the subsequent meal, is unclear. We manipulated eating rate(More)
Vitamin D is an essential nutrient for maintaining bone health. Recent data suggest that vitamin D and calcium supplementation might affect stress fracture incidence in military personnel. Although stress fracture is a health risk for military personnel during training, no study has investigated changes in vitamin D status in Soldiers during United States(More)
BACKGROUND Cardiometabolic disease risk in US military recruits and the effects of military training have not been determined. This study examined lifestyle factors and biomarkers associated with cardiometabolic risk in US Army recruits (209; 118 male, 91 female, 23 ± 5 yr) before, during, and after basic combat training (BCT). METHODOLOGY/PRINCIPAL(More)
OBJECTIVE This study investigated whether a stressful military training program, the 9- to 10-week U.S. Army basic combat training (BCT) course, alters the cognitive performance and mood of healthy young adult females. BACKGROUND Structured training programs including adolescent boot camps, sports training camps, learning enrichment programs, and military(More)
High eating behavior self-efficacy may contribute to successful weight loss. Diet interventions that maximize eating behavior self-efficacy may therefore improve weight loss outcomes. However, data on the effect of diet composition on eating behavior self-efficacy are sparse. To determine the effects of dietary glycemic load (GL) on eating behavior(More)
BACKGROUND It is reported that women are more susceptible to stress than men but they have not been compared in stressful, real-world, team-centered, occupational/training environments. This study investigated effects of Army Basic Combat Training (BCT), a structured military training program, on the mood of young adult men and women. METHODS Using the(More)
Energy deficit and dietary macronutrient intake are thought to independently modulate cognition, mood and sleep. To what extent manipulating the dietary ratio of protein-to-carbohydrate affects mood, cognition and sleep during short-term energy deficit is undetermined. Using a randomized, block design, 39 non-obese young adults (21±1 years, BMI 25±1(More)
OBJECTIVE To examine the effects of diets varying in carbohydrate and glycemic index (GI) on changes in body composition, resting metabolic rate (RMR), and metabolic adaptation during and after weight loss. METHODS Adults with obesity (n = 91) were randomized to one of four provided-food diets for 17 weeks. Diets differed in percentage energy from(More)
BACKGROUND Vitamin D is an essential nutrient for maintaining bone health, to include protecting against stress fracture during periods of rapid bone turnover. The objective of this longitudinal, observational study was to assess vitamin D status, biomarkers of bone turnover, and vitamin D and calcium intake in female Soldiers (n = 91) during US Army basic(More)
Fat-free mass (FFM) adaptations to physical training may differ between sexes based on disparities in fitness level, dietary intake, and levels of plasma amino acids (AA). This investigation aimed to determine FFM and plasma AA responses to military training, examine whether adaptations differ between male and female recruits, and explore potential(More)
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