Simple measures of dietary variety are associated with improved dietary quality.

The objective of this study was to identify a measure of dietary variety that was associated with improved dietary quality and easily understood by consumers. Dietary quality was measured by nutrient adequacy and intakes of added sugars, saturated fat, cholesterol, and sodium. We developed four definitions of dietary variety: (a) a count of basic commodities consumed; (b) a count of food codes reported; (c) a count of five Food Guide Pyramid (FGP) food groups consumed; and (d) a count of 22 FGP subgroups consumed. The analysis sample included 4,964 men and 4,797 women aged 19 years and older who participated in the Continuing Survey of Food Intakes by Individuals 1994-96. For each day of dietary data, we examined associations of each type of dietary variety with several measures of dietary quality using Spearman's correlations and multivariate linear regression models. After adjusting for energy intake and the number of FGP food group servings, all types of dietary variety were positively associated with mean nutrient adequacy across 15 nutrients, but associations were strongest for commodity-based variety and for 22 FGP subgroup consumption variety. Likewise, all variety measures were inversely associated with intakes of added sugars and saturated fat, with commodity-based variety and 22 FGP subgroup variety the strongest. We conclude that variety measured using 22 FGP subgroups is preferable because it is a good predictor of dietary quality, is relatively simple to calculate, and is easy to explain to consumers.

Dietary variety increases the probability of nutrient adequacy among adults.

Despite guidance to consume a variety of foods, the role of dietary variety in ensuring nutrient adequacy is unclear. The aim of this study was to determine whether a commodity-based measure of dietary variety was associated with the probability of nutrient adequacy after adjusting for energy and food group intakes. Subjects were 4969 men and 4800 women >/= 19 y old who participated in the Continuing Survey of Food Intakes for Individuals 1994-1996. Using 24-h recall data, the mean probability of adequacy across 15 nutrients was calculated using the Dietary Reference Intakes. Dietary variety was defined using a commodity-based method similar to that used for the Healthy Eating Index (HEI). Associations were examined in gender-specific multivariate regression models. Energy intake was a strong predictor of the mean probability of adequacy in models controlled for age, BMI, education level, and ethnicity (model R(2) = 0.60 and 0.54 for men and women, respectively). Adding the number of servings from each of the 5 Food Guide Pyramid (FGP) groups to the models significantly improved the model fit (R(2) = 0.69 and 0.66 for men and women). Adding dietary variety again significantly improved the model fit for both men and women (R(2) = 0.73 and 0.70, respectively). Variety counts within the dairy and grain groups were most strongly associated with improved nutrient adequacy. Dietary variety as defined by the HEI contributes an additional component of dietary quality that is not captured by FGP servings or energy intake.

Did fat intake in the United States really decline between 1989-1991 and 1994-1996?

The objectives of this study were to determine changes in fat and energy intakes in the United States between 1989-1991 and 1994-1996, and to examine the implications of expressing fat intake in grams vs as a percent of total energy intake. The source of data was the Continuing Survey of Food Intake by Individuals. The results suggest that intake of energy rose between the 2 time periods, primarily due to higher carbohydrate intake. There was also a modest increase in fat intake. However fat intake, as a percent of total energy, declined. The higher energy intakes were primarily from beverages, especially soft drinks, food mixtures, grain snacks, and pastries. The primary sources of higher fat intakes were meat mixtures, vegetables, and some categories of the grain group. Similar trends in the Food Supply Series suggested that the changes observed were not entirely due to changes in survey methodology. Because the increase in fat intake was masked by the increase in energy intake, we conclude that assessing trends in fat intake as a percent of energy consumption can be misleading, unless information on total energy and fat intake, in grams, is also provided. These preliminary findings should be interpreted cautiously until they are confirmed by formal secular trend analyses.