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[Definitie:] "An ergogenic aid is any substance or phenomenon that enhances performance."
(Wilmore and Costill) 
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2 6 - 1 1 - 2 0 0 4 Effects of a Low–Glycemic on Resting Energy Expenditure Heart Disease Risk Factors During Weight Loss
Mark Pereira,
Janis Swain,
Allison Goldfine,
Nader Rifai,
David Ludwig
Context Weight loss elicits physiological adaptations relating to energy intake and expenditure that antagonize ongoing weight loss.
Objective To test whether dietary composition affects the physiological adaptations to weight loss, as assessed by resting energy expenditure.
Design, Study, and Participants A randomized parallel-design study of 39 overweight or obese young adults aged 18 to 40 years who received an energy-restricted diet, either low–glycemic load or low-fat. [Tabel]
Glycemic load was reduced by modifications of both the amount and type of carbohydrate. Thus, some high– glycemic index carbohydrate in the lowfat diet (eg, conventional bread, instant oatmeal, corn) was replaced with food that had other macronutrients (eg, cheese, soy, vegetable oil) or a low glycemic index (eg, whole kernel bread, steel-cut oats, pasta). Mean daily predicted glycemic load was calculated as grams of available carbohydrate glycemic index (using white bread as 100%) and summed over all foods.
Total energy intake for the low– glycemic load and low-fat groups was 60%of energy requirements, with a minimum of 1100 kcal/d.
Participants were studied in the General Clinical Research Centers of the Brigham and Women’s Hospital and the Children’s Hospital, Boston, Mass, before and after 10% weight loss. The study was conducted from January 4, 2001, to May 6, 2003.
Main Outcome Measures Resting energy expenditure measured in the fasting state by indirect calorimetry, body composition by dual-energy x-ray absorptiometry, cardiovascular disease risk factors, and self-reported hunger.
Results Resting energy expenditure (REE) decreased less with the low–glycemic load diet than with the low-fat diet, expressed in absolute terms (mean [SE], 96 [24] vs 176 [27] kcal/d; P=.04) or as a proportion (5.9% [1.5%] vs 10.6% [1.7%]; P=.05).
Participants receiving the low–glycemic load diet reported less hunger than those receiving the low-fat diet (P=.04). Insulin resistance (P=.01), serum triglycerides (P=.01), C-reactive protein (P=.03), and blood pressure (P=.07 for both systolic and diastolic) improved more with the low–glycemic load diet.
Changes in body composition (fat and lean mass) in both groups were very similar (P=.85 and P=.45, respectively).
Conclusions Changes in dietary composition within prevailing norms can affect physiological adaptations that defend body weight. |
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