Many children and adolescents in the United States have diets that supply marginal amounts of several nutrients. Recent studies of the diets of children and adolescents have shown an increase in the consumption of energy-dense, modest-nutrient-density foods, possibly at the expense of foods that are good sources of essential nutrients. There also has been a dramatic increase in obesity rates in American children and adolescents. Kant performed the first study evaluating the impact of modest-nutritional-value foods on the diets of American children and adolescents.

Participants were chosen from the third National Health and Nutrition Examination Survey. Children and adolescents eight to 18 years of age were given a questionnaire, a full medical examination, and a battery of laboratory tests. A trained interviewer performed the dietary assessment using a 24-hour recall method. Low-nutrient-density food categories included visible fats (e.g., butter, oil), sweeteners, candy, sweetened beverages, baked and dairy desserts, salty snacks, and miscellaneous (e.g., coffee, tea).

A total of 4,852 participants were included in the study. Low-nutrient-density foods accounted for more than 30 percent of the daily energy intake. Of these foods, the most commonly consumed were sweeteners and desserts. Total energy intake and the percentage of energy from carbohydrates and fats were positively related to an increase in the consumption of low-nutrient–density foods, but the percentage of energy from protein and dietary fiber was inversely related to the number of low-nutrient-density foods consumed. Consumption of low-nutrient-density foods had a negative impact on the amount of nutrient-dense foods consumed. In addition, the mean intake of several micronutrients declined as low-nutrient-density food consumption increased. The consumption of low-nutrient-density foods was not a significant predictor of body mass index.

The author notes that nearly one third of the daily energy intake of American children and adolescents comes from relatively energy-dense, low-nutritional-value foods. The author adds that high intake of low-nutrient-density foods is related to an overall higher energy intake and a lower intake of the major food groups and micronutrients.