J Am Diet Assoc
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Randomized Controlled Trial
Blood ketones are directly related to fatigue and perceived effort during exercise in overweight adults adhering to low-carbohydrate diets for weight loss: a pilot study.
Ketogenic diets have been associated with reductions in free-living physical activity, a response that can be counterproductive in individuals trying to lose weight. To explore whether popular low-carbohydrate diets might impact the desire to exercise by raising blood ketone concentrations, fatigue and perceived effort during exercise were compared in untrained, overweight adults adhering to a ketogenic low-carbohydrate diet or to a control diet low in carbohydrate, but not ketogenic (5%, 65%, and 30% or 40%, 30%, and 30% of energy from carbohydrate, fat, and protein, respectively). In this prospective, randomized, 2-week pilot study, all meals and snacks were provided to subjects, and energy intake was strictly controlled to provide approximately 70% of that needed for weight maintenance. ⋯ At week 2, blood beta-hydroxybutyrate concentrations were 3.6-fold greater for the ketogenic vs nonketogenic group (P=0.018) and correlated significantly with perceived exercise effort (r2=0.22, P=0.049). Blood beta-hydroxybutyrate was also significantly correlated to feelings of "fatigue" (r=0.458, P=0.049) and to "total mood disturbance" (r=0.551, P=0.015) while exercising. These pilot data indicate that ketogenic, low-carbohydrate diets enhance fatigability and can reduce the desire to exercise in free-living individuals.
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Comparative Study
A dietary quality comparison of popular weight-loss plans.
Popular weight-loss plans often have conflicting recommendations, which makes it difficult to determine the most healthful approach to weight loss. Our study compares the dietary quality of popular weight-loss plans. Dietary quality, measured by the Alternate Healthy Eating Index (AHEI), was calculated via sample menus provided in published media for the New Glucose Revolution, Weight Watchers, Atkins, South Beach, Zone, Ornish, and 2005 US Department of Agriculture Food Guide Pyramid (2005 Food Guide Pyramid) plans. ⋯ Of a maximum possible score of 70, the AHEI scores for each weight-loss plan from the highest to the lowest plan were: Ornish (score 64.6), Weight Watchers high-carbohydrate (score 57.4), New Glucose Revolution (score 57.2), South Beach/Phase 2 (score 50.7), Zone (score 49.8), 2005 Food Guide Pyramid (score 48.7), Weight Watchers high-protein (score 47.3), Atkins/100-g carbohydrate (score 46), South Beach/Phase 3 (score 45.6), and Atkins/45-g carbohydrate (score 42.3). Dietary quality varied across popular weight-loss plans. Ornish, Weight Watchers high-carbohydrate, and New Glucose Revolution weight-loss plans have an increased capacity for cardiovascular disease prevention when assessed by the AHEI.
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Randomized Controlled Trial Multicenter Study
The PREMIER intervention helps participants follow the Dietary Approaches to Stop Hypertension dietary pattern and the current Dietary Reference Intakes recommendations.
To examine the influence of the PREMIER study lifestyle interventions on dietary intakes and adherence to the Dietary Approaches to Stop Hypertension (DASH) dietary pattern and the Dietary Reference Intakes (DRI). ⋯ Both the established intervention and established intervention plus DASH dietary pattern group intervention were effective in helping participants follow established recommendations to control blood pressure. The advice-only control group also made some behavior changes, mainly decreasing energy and sodium intake. Only the established intervention plus DASH dietary pattern group significantly increased intakes of DASH-specific food groups, including fruits, vegetables, and dairy products, and nutrients, including protein, fiber, calcium, potassium, and magnesium. Most of the increases did not reach the levels consumed in the original DASH feeding studies. Whereas the established intervention plus DASH dietary pattern group intervention provides a useful platform to achieve the DASH dietary pattern and current DRI recommendations, intervention enhancements, including a greater emphasis on nutrient-dense foods, would likely improve this intervention.
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Randomized Controlled Trial
Multi-school collaboration to develop and test nutrition computer modules for pediatric residents.
The provision of essential nutrition-related content in US medical education has been deficient, despite efforts of the federal government and multiple professional organizations. Novel and efficient approaches are needed. A multi-department project was developed to create and pilot a computer-based compact disc instructional program covering the nutrition topics of oral rehydration therapy, calcium, and vitamins. ⋯ Study group resident attitudes toward computer-based instruction improved. Use of these computer modules prompted almost half of the residents in the study group to independently pursue relevant nutrition-related information. This inexpensive, collaborative, multi-department effort to design a computer-based nutrition curriculum positively impacted both resident knowledge and attitudes.