The Safety and Efficacy of Low and High Carbohydrate Diets

This study will compare the safety and effectiveness of a low carbohydrate diet (Atkins Diet) with a high carbohydrate diet (conventional USDA diet).

Despite the considerable mass appeal of popular diet books, such diet approaches lack data to support their efficacy and safety. Despite its widespread use for more than 30 years, the Atkins diet has never been evaluated in a large, randomized, controlled trial. This study will assess the short-term and long-term clinical effects of a low-carbohydrate diet and a high-carbohydrate diet in overweight and obese men and women.

Participants in this study will be randomly assigned to the Atkins diet (low-carbohydrate, unlimited fat and protein) or a conventional USDA diet (high-carbohydrate, low fat). The study will evaluate the effects of each dietary approach on changes in: 1) weight and body composition, 2) metabolic and organ function, 3) exercise tolerance. Each participant will be enrolled in the study for 2 years.

• Behavioral: Low- Carbohydrate -Atkins Diet
  Low Carbohydrate Diet
  Other Name: low carb
• Behavioral: Low Calorie Diet
  Maintain a low calorie diet
  Other Name: low cal

• Active Comparator: Low Carb
  Low Cabohydrate Diet: 20 week of weekly group behavior modification, 20 weekly bi-weekly, bi-monthly to finish
  Intervention: Behavioral: Low- Carbohydrate -Atkins Diet
• Active Comparator: Low Calorie
  Low Calorie Diet: 20 weeks of weekly behavior modification, 20 weekly of bi-weekly, bimonthly to finish 2 years
  Intervention: Behavioral: Low Calorie Diet

• Friedman AN, Ogden LG, Foster GD, Klein S, Stein R, Miller B, Hill JO, Brill C, Bailer B, Rosenbaum DR, Wyatt HR. Comparative effects of low-carbohydrate high-protein versus low-fat diets on the kidney. Clin J Am Soc Nephrol. 2012 Jul;7(7):1103-11. Epub 2012 May 31.
• Borradaile KE, Halpern SD, Wyatt HR, Klein S, Hill JO, Bailer B, Brill C, Stein RI, Miller BV 3rd, Foster GD. Relationship between treatment preference and weight loss in the context of a randomized controlled trial. Obesity (Silver Spring). 2012 Jun;20(6):1218-22. doi: 10.1038/oby.2011.216. Epub 2011 Jul 14.
• Foster GD, Wyatt HR, Hill JO, Makris AP, Rosenbaum DL, Brill C, Stein RI, Mohammed BS, Miller B, Rader DJ, Zemel B, Wadden TA, Tenhave T, Newcomb CW, Klein S. Weight and metabolic outcomes after 2 years on a low-carbohydrate versus low-fat diet: a randomized trial. Ann Intern Med. 2010 Aug 3;153(3):147-57.

Inclusion Criteria:

• Body mass index between 30 and 40
• Live and work within 1 hour of the study site
• Stable psychological status

Exclusion Criteria:

• History of heart disease, heart attack, or stroke
• Blood pressure > 140/90 mmHG
• Abnormal cholesterol levels
• Significant psychiatric illness
• Any medication that affects weight or metabolic rate
• Presence or history of a chronic disease that is known to affect appettite, food intake, or metabolism (i.e. diabetes, thyroid disease or cancer).
• Currently using antidepressants, steroids, tobacco or illegal drugs
• Pregnant, breastfeeding, or planning pregnancy
• 10 lb change in weight within 6 months of study entry
• History of malignant arrhythmias or cerebrovascular, renal, or hepatic disease
• History of protein wasting diseases or gout
• Severe arthritis
• Osteoperosis
• Certain types of hormone replacement therapy
• Currently following a vegetarian diet

• National Center for Complementary and Alternative Medicine (NCCAM)
• National Institutes of Health (NIH)