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


METHODS
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.
Gardner
Christopher D
CD
Stanford Prevention Research Center and Department of Medicine, Stanford University Medical School, Stanford, CA, USA. cgardner@stanford.edu
Kim
Soowon
S
Bersamin
Andrea
A
Dopler-Nelson
Mindy
M
Otten
Jennifer
J
Oelrich
Beibei
B
Cherin
Rise
R
D000328:Adult; D018798:Anemia, Iron-Deficiency / Q000209:etiology; D001361:Avitaminosis / Q000209:etiology; D003677:Deficiency Diseases / Q000209:etiology*; D004038:Diet, Reducing / Q000009:adverse effects / Q000145:classification / Q000592:standards; D002149:Energy Intake; D005260:Female; D006801:Humans; D008275:Magnesium Deficiency / Q000209:etiology; D018977:Micronutrients / Q000008:administration & dosage*; D008875:Middle Aged; D012307:Risk Factors
D018977:Micronutrients