Whole-grain consumption is associated with diet quality and nutrient intake in adults: the National Health and Nutrition Examination Survey, 1999-2004

Background: The consumption of whole grains and its association with nutrient intake has not been assessed in a recent nationally representative population.

Objective: To examine the association of consumption of whole grains, using the new whole-grain definition, with diet quality and nutrient intake in a recent, nationally representative sample of adults.

Design: Secondary analysis of cross-sectional data from 1999-2004 National Health and Nutrition Examination Survey.

Participants and methods: Adults aged 19 to 50 years (n=7,039) and aged 51 years and older (n=6,237).

Main outcome measures: Participants were divided into four whole-grain consumption groups: ≤0 to <0.6, ≥0.6 to <1.5, ≥1.5 to <3.0, and ≥3.0 servings (ounce equivalents)/day. Macro- and micronutrient intakes and diet quality, using the Healthy Eating Index, were determined for each group.

Statistical analyses: Sample weights were applied. The percentages of adults in whole-grain consumption groups were calculated. The covariates used were energy, ethnicity, sex, and age. Least-square means were calculated. P for linear trend analysis was determined using whole-grain intake as a linear covariate. A P value of ≤0.05 was considered significant.

Results: Adults aged 19 to 50 and 51+ years consumed a mean of 0.63 and 0.77 servings of whole grains per day, respectively. For both age groups, diet quality and intake of energy, fiber, and polyunsaturated fatty acids were significantly higher in those consuming the most servings of whole grains. Intake of total sugars (19 to 50 year age group only), added sugars, saturated fatty acids, monounsaturated fatty acids, and cholesterol was significantly lower in those consuming the most servings of whole grains. Intake of all micronutrients, except vitamin B-12 and sodium, was higher among individuals who consumed the most servings of whole grains.

Conclusions: Overall consumption of whole grains in the US population was low using the recently updated whole-grain definition. Adults who consumed the most servings of whole grains had better diet quality and nutrient intakes.