Snacking, Obesity, Cardiovascular Fitness and Television Viewing Among Adolescents

Abstract

Possible relationships among snacking, obesity, cardiovascular fitness and television viewing were examined in a group of 54 14-and 15-year old adolescents. Dietary intake was estimated using a 24-hour recall and 2-day food record for which subjects were asked to identify all foods and beverages consumed as either a meal or snack. The three days of intake were analyzed by the University of Minnesota Nutrient Data System for total nutrient intake (meals + snacks) and again for snacks alone. A nutrient adequacy ratio (NAR) and mean adequacy ratio (MAR) were calculated for the total intake (meals + snacks) using nutrients with an established Recommended Dietary Allowance. Skinfold thicknesses were measured to calculate percentage body fat (%BF). Males with >20 %BF and females with >30 %BF were classified as obese. A modified Harvard step test assessed cardiovascular fitness. A 24-hour activity recall and 2-day activity record estimated the hours spent viewing television. Statistical analysis included Students t-Test and Pearson's product moment analysis. Over 40% of both male and female subjects were classified as obese. Males reported a significantly higher NAR for vitamin D, folate, calcium, magnesium and iron when compared to females (p<.01), although the MAR between the two groups was not different (p>.05). Males reported an average of 2.6 snacks per day compared to the 1.9 snacks reported by females (p>.05). Snacks provided more than 25% of energy and more than 20% of the total intake for several nutrients, including calcium, magnesium, and vitamins A, E and C. Females had a mean step test score which suggested a lower level of cardiovascular fitness when compared to males (p<.05); however the mean score for both groups was below average. Males and females reported viewing television for an average of 3.6 and 4.5 hours, respectively (p>.05). A significant correlation between the hours of television viewed and the number of snacks consumed was not identified (r=.05, p=.74). Likewise there was no significant correlation identified between the hours of television viewed and obesity (r=−.28, p=.50), television and cardiovascular fitness (r=.24, p=.104), and the number of snacks consumed and fitness score (r=−.05, p=.712). These results suggest that snacks can make important contributions to the overall nutrient intake of adolescents. In addition, these results suggest that snacking and television viewing may not be linked directly to obesity, which are contrary to previous findings. Supported in part by the Texas Agricultural Experiment Station.