Low Carbohydrate and Conventional Diets Associated to Resistance Training on Muscle Fitness and Health Markers (LCD-RT)
The purpose of this study was to compare the effects of two different diets (low carbohydrate - LCD and conventional - CONV) on body composition, strength performance, muscle mass and biomarkers of health in overweight adults submitted to resistance training (RT). It has been hypothesized that LCD would produce higher rates of weight loss and that both diets would be useful to maintain muscle mass and strength and biomarkers of health.
|Study Design:||Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||Combined Effects of Resistance Training and Low Carbohydrate or Conventional Diets on Strength, Muscle Mass, Body Composition, Blood Lipids and Endothelium Function|
- body mass [ Time Frame: eight weeks ] [ Designated as safety issue: No ]Measured always at the same time of the day on a calibrated weight scale
- Muscle strength [ Time Frame: eight weeks ] [ Designated as safety issue: No ]Measured using resistance exercise machines (isotonic) in four exercise movements
- Endothelial function [ Time Frame: eight weeks ]Measured using a two dimensional color spectral Doppler ultrasound equipped with a 14MHz linear transducer. Subject laid down comfortably in the supine position with the right arm slightly abduced. After locating the brachial artery, the transducer was placed on the anteromedial face of the right arm, perpendicular to the centerline of the arm, 5-10 cm above the antecubital fossa, over the artery.
- muscle thicknesses [ Time Frame: eight weeks ]Measured with a ultrasoundo bidimensional in Mode B, with a 7,5MHz transducer on the anatomical sites knee extensor muscles and elbow flexors and extensors.
- markers of renal function [ Time Frame: eight weeks ]Measured using conventional and satandardized laboratory methods with subjects fasting for 12 hours
- body composition [ Time Frame: eight weeks ]Measured with skinfold calipers and using prediction equations to determine body fat and lean body mass.
|Study Start Date:||September 2006|
|Study Completion Date:||August 2008|
|Primary Completion Date:||January 2008 (Final data collection date for primary outcome measure)|
Experimental: Diet counseling
Outcomes of the study may enhance diet counseling
|Other: macronutrient and energy manipulation|
|Experimental: exercise training||Other: macronutrient and energy manipulation|
Overweight and obesity prevalence has increased worldwide. Current guidelines recommend health behavior modifications, including better eating habits and regular physical activity (including resistance training - RT) as a strategy to control and prevent the problem. Traditionally, diets poor in energy and fat (conventional diets - CONV) have been recommended to promote losses in body and fat masses; however, there has been recently a growing interest in the academic community to investigate the effects of low carbohydrate diet (LCD) on health outcomes, since this kind of diet appears to be more effective for reducing body mass as compared to CONV. Nevertheless, evidences are scarce regarding the effects of LCD associated to RT on body composition, strength performance, blood lipids, endothelium function and other markers of health, demanding the development of clinical trials aiming to determine the combined health effects of these interventions.