Purpose: Recent public health messages have advised consumers to lower dietary energy density (ED) for weight management, but it is not known whether the proportion of the diet from low-ED foods is related to weight status. In a nationally representative sample of US adults, we evaluated whether the proportions of dietary energy intake contributed by low- and high-ED foods are associated with body mass index (BMI) and waist circumference (WC).
Methods: Data were from a cross-sectional sample of 9551 adults ≥18 years in the 2005-2008 National Health and Nutrition Examination Survey (NHANES). ED (kcal/g) was calculated for each food item reported during a 24-h dietary recall; individual foods were divided into five ED categories: very low ED (<0.6 kcal/g), low ED (0.6-1.5 kcal/g), medium ED (1.51-2.25 kcal/g), high ED (2.26-4.0 kcal/g), and very high ED (>4.0 kcal/g). The percentages of total energy and the food weight from each category were evaluated by BMI and WC after controlling for total energy intake and other covariates.
Results: Men classified as lean (BMI < 25 kg/m2) reported consuming a greater proportion of total energy from very low- and low-ED foods (7.2 %very low and 23.3 %low), compared to men considered obese ((BMI > 30 kg/m2); 5.2 %very low and 20.1low %; p-trends <0.001very low, 0.002low). Similarly, women classified as lean reported intakes of very low-ED foods of 7.8 % (vs. 6.4 % for women with obesity) of total energy and low-ED foods of 24.7 % (vs. 21.5 % for women with obesity) of total energy (p-trends 0.007very low, 0.004low). Men and women with obesity reported greater proportions of energy from high-ED foods (45.9 %men with obesity vs. 42.4 %lean men, 44.2 %women with obesity vs. 39.9 %lean women) with significant statistical trends (men = 0.008, women = 0.0005). Similar patterns were observed for intakes of proportions of very low-, low-, and high-ED foods and WC.
Conclusion: Higher proportions of energy intake and food weight contributed by very low- and low-ED foods are associated with lower BMI (and WC).
Keywords: Body mass index; Energy density; Fruits and vegetables; NHANES; Obesity; Waist circumference.