Micronutrient quality of weight-loss diets that focus on macronutrients: results from the A TO Z study

• Published in: The American journal of clinical nutrition 2010-08, Vol.92 (2), p.304-312
• Main Authors: Gardner, Christopher D, Kim, Soowon, Bersamin, Andrea, Dopler-Nelson, Mindy, Otten, Jennifer, Oelrich, Beibei, Cherin, Rise
• Format: Article
• Language: English
• Subjects: Adult; Anemia, Iron-Deficiency - etiology; ascorbic acid; Atkins diet; Avitaminosis - etiology; Biological and medical sciences; Comparative analysis; Deficiency Diseases - etiology; Diet; Diet, Reducing - adverse effects; Diet, Reducing - classification; Diet, Reducing - standards; diet-related diseases; dietary minerals; dieting; Energy Intake; Feeding. Feeding behavior; Female; folic acid; Fundamental and applied biological sciences. Psychology; human diseases; human nutrition; Humans; iron; LEARN diet; macronutrient distribution; magnesium; Magnesium Deficiency - etiology; Micronutrients - administration & dosage; Middle Aged; nutrient intake; Nutrition; nutritional adequacy; Nutritional Status, Dietary Intake, and Body Composition; Obesity; Original Research Communications; Ornish diet; overweight; Risk Factors; Studies; thiamin; Vertebrates: anatomy and physiology, studies on body, several organs or systems; vitamin A; vitamin B12; vitamin E; vitamin K; vitamins; Weight control; weight control programs; Women; zinc; Zone diet
• ISSN: 0002-9165; 1938-3207
• DOI: 10.3945/ajcn.2010.29468

BACKGROUND: Information on the micronutrient quality of alternative weight-loss diets is limited, despite the significant public health relevance. OBJECTIVE: Micronutrient intake was compared between overweight or obese women randomly assigned to 4 popular diets that varied primarily in macronutrient distribution. DESIGN: Dietary data were collected from women in the Atkins (n = 73), Zone (n = 73), LEARN (Lifestyle, Exercise, Attitudes, Relationships, Nutrition) (n = 73), and Ornish (n = 72) diet groups by using 3-d, unannounced 24-h recalls at baseline and after 8 wk of instruction. Nutrient intakes were compared between groups at 8 wk and within groups for 8-wk changes in risk of micronutrient inadequacy. RESULTS: At 8 wk, significant differences were observed between groups for all macronutrients and for many micronutrients (P < 0.0001). Energy intake decreased from baseline in all 4 groups but was similar between groups. At 8 wk, a significant proportion of individuals shifted to intakes associated with risk of inadequacy (P < 0.05) in the Atkins group for thiamine, folic acid, vitamin C, iron, and magnesium; in the LEARN group for vitamin E, thiamine, and magnesium; and in the Ornish group for vitamins E and B-12 and zinc. In contrast, for the Zone group, the risk of inadequacy significantly decreased for vitamins A, E, K, and C (P < 0.05), and no significant increases in risk of inadequacy were observed for other micronutrients. CONCLUSIONS: Weight-loss diets that focus on macronutrient composition should attend to the overall quality of the diet, including the adequacy of micronutrient intakes. Concerning calorie-restricted diets, there may be a micronutrient advantage to diets providing moderately low carbohydrate amounts and that contain nutrient-dense foods.