The Effect of an 8-Week Aerobic Exercise Program on the Diet and Eating Behaviours of Adolescents with a Normal Weight and Excess Body Weight

Abstract

Introduction: Health-related behaviours of Canadian adolescents are generally suboptimal. Studies have assessed effectiveness of exercise interventions primarily from an energy balance perspective, but not from a health promotion standpoint. This study assessed the effect of an 8-week aerobic exercise program on dietary intake parameters and eating behaviours of adolescents with a normal weight and excess body weight. Methods: This quasi-experimental study involved 13 male and 13 female adolescents between the age of 14-18 years old (17 normal weight, 9 with excess weight). The intervention consisted of an 8-week aerobic exercise program on cycle ergometers, aiming for 50-75% of heart rate reserve. Diet was assessed in pre- and post-intervention via 24-hour dietary recalls. Two recalls were collected for each condition: pre- intervention, post-intervention on exercise days and post-intervention on non-exercise days. Diet was assessed for the following dietary intake parameters: food quantity, diet quality and eating patterns. Results: The 8-week exercise program led to a decrease in meal size at lunch and dinner, energy density at breakfast, carbohydrate intake as well as a slight shift in eating pattern of participants. At baseline, participants with excess weight had greater number of daily eating occurrences and portion sizes at evening snacks but consumed a smaller percentage of daily energy intake before school, compared to those with a normal weight. Participants with excess weight decreased their total number of eating occurrences, but not those with normal weight. The exercise program did not influence cognitive restraint, uncontrolled eating or emotional eating scores of participants. Conclusion: Significant changes in food quantity and eating pattern parameters, but not in diet quality, were observed following the exercise program. Differences in pre- intervention and in response to the exercise program were observed based on weight status. Future studies with greater sample size are needed to confirm these findings.