Nutrient intakes and snacking frequency in female students

Background: Snacking can have the negative image of being detrimental to the diet, because snack foods are commonly thought of as providing only 'empty calories'--high in energy but low in micronutrients. This observational study looked at the nutrient density of snacks and meals, and at the effect of eating frequency on mean daily nutrient intakes in 44 female students (aged 17-26 years). Methods: Baseline dietary data from an existing intervention study were reanalysed. Eating occasions, taken from 7-day weighed food diaries, were classified as meals or snacks by time of day, and the composition of meals and snacks compared. Subjects were divided into tertiles by eating frequency and their nutrient intakes compared. Results: As eating frequency increased, the number of snacks and the number of different snack items in the diet increased, while the number of meals remained constant. Snacks, overall, were significantly lower in percentage non-alcohol energy from fat and higher in percentage non-alcohol energy from carbohydrate. Snacks had lower nutrient densities than meals for non-starch polysaccharide (NSP), minerals and vitamins except vitamin C. However, there were no significant differences between the top and bottom tertiles of snacking frequency for overall percentage energy from fat, protein or carbohydrate, or intakes of micro-nutrients. The top tertile tended to be leaner and have higher energy intakes than infrequent eaters (not significant). There was a significant negative correlation between eating frequency and body mass index (BMI). Conclusions: It is concluded that snacking per se did not compromise diet quality in this group, and that those with a high snacking frequency were eating more in general and choosing a wider variety of foods, resulting in a balanced intake of nutrients.