Effectiveness of a Low Carbohydrate Diet Versus a High Carbohydrate Diet in Promoting Weight Loss and Improved Health
This study will examine the effects of a low carbohydrate diet versus a high carbohydrate diet on weight loss.
Behavioral: Atkins diet (low carbohydrate diet)
Behavioral: DASH diet (high carbohydrate diet)
|Study Design:||Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||Metabolic Consequences of High and Low Carbohydrate Diets|
- Weight loss [ Time Frame: monthly ] [ Designated as safety issue: Yes ]Excess weight loss (greater than 5 pounds a week)would trigger patient assessment.
- Risk of cardiovascular disease [ Time Frame: Every six months ] [ Designated as safety issue: Yes ]Elevated lipids or rising blood pressure during six month safety assessments would trigger additional participant evaluation
- bone health [ Time Frame: end of study ] [ Designated as safety issue: No ]
- kidney function [ Time Frame: every six months ] [ Designated as safety issue: No ]
- neuroendocrine mechanisms of hunger and satiety [ Time Frame: end of study ] [ Designated as safety issue: No ]
|Study Start Date:||April 2005|
|Study Completion Date:||June 2010|
|Primary Completion Date:||March 2009 (Final data collection date for primary outcome measure)|
Experimental: Atkins Diet
Participants randomized to this arm will consume a low carbohydrate diet as described by Dr. Robert Atkins in his book: Dr. Atkins' New Diet Revolution New York: Avon Books, 2002.
|Behavioral: Atkins diet (low carbohydrate diet)|
Active Comparator: DASH Diet
Participants randomized to this arm will consume the Dietary Approaches to Stop Hypertension (DASH) diet as described here: http://www.nhlbi.nih.gov/health/public/heart/hbp/dash/new_dash.pdf
|Behavioral: DASH diet (high carbohydrate diet)|
The number of overweight and obese Americans has increased significantly in recent years. There are now many different diet plans being promoted by doctors and the media. The Atkins diet, a low carbohydrate nutritional plan, is especially popular; its advocates claim that following the diet will result in long-term weight loss with no negative effects. Another diet, called the Dietary Approaches to Stop Hypertension (DASH) diet, is a high carbohydrate diet designed to help treat and prevent high blood pressure. However, more thorough investigation of these claims is needed. This study will compare the short- and long-term effects of the Atkins diet to the (DASH) diet. This trial will enroll overweight and obese participants.
This study will last 30 months and will comprise two phases. Participants will be randomly assigned to either the Atkins or DASH diet for 30 months. During Phase 1, all participants will undergo 6 months of weekly group therapy to encourage weight loss. Phase 2 is a weight loss maintenance phase. During Phase 2, participants will have monthly meetings with a therapist for weight loss support. Study visits will occur at study entry and at Months 3 and 30. At each study visit, weight measurements, blood and urine collection, and x-rays will occur to determine participants' weight loss, cardiovascular health, kidney function, and bone density.
|United States, Oregon|
|Kaiser Permanente Center for Health Research|
|Portland, Oregon, United States, 97227|
|Principal Investigator:||Njeri Karanja, PhD||Kaiser Permanente Northwest, Center for Health Research|