Objective: The purpose of this study was to determine whether obese adolescents eat more high-calorie low-nutrient-dense foods than non-obese adolescents.
Research methods and procedures: Using a cross-sectional design, 22 non-obese and 21 obese adolescents kept 14-day food records. Records provided estimates of total daily energy intake and caloric intake from five categories of high-calorie, low-nutrient-dense (HC) foods: candy, chips, soda, baked goods, and ice cream. Body composition was determined by 18O dilution and daily energy expenditure by doubly labeled water. Percentage of energy intake reported (%report) was calculated as the ratio of reported energy intake to measured energy expenditure (x 100%).
Results: Both groups underreported energy intake, but the percentage reported was significantly greater in the non-obese group (78.2+/-20.5% non-obese vs. 55.5+/-21.8% obese, p<0.001). Consumption of calories from chips and soda was similar among non-obese and obese adolescents. However, total energy intake from all HC foods was higher in the non-obese group than among the obese (617+/-356 kcal/day vs. 362+/-223 kcal/day; p<0.01) and represented 27.2+/-10.5% and 19.9+/-9.6% of reported energy intake in the non-obese and obese groups, respectively. After adjustment for under-reporting, the percentage of calories provided by each of the HC foods was similar in the obese and non-obese groups except for ice cream, which remained significantly greater in the non-obese group (p<0.05).
Discussion: Our findings suggest that both non-obese and obese adolescents consume a substantial portion of reported calories from HC foods and that obese adolescents do not consume more calories from these foods than non-obese adolescents. These data offer no evidence to support the widespread notion that obese adolescents eat more "junk food" than non-obese adolescents. Health professionals who treat obese adolescents must be aware that the excess calories in their diets may come from a variety of food sources and not solely from high-calorie snack foods.