The Effect of Dietary Habits and Physical Activity on Body Mass Index in High School Adolescents in a Regional Urban Area

Background: The probability of interaction between dietary habits and physical activity in the risk of obesity and health problems is an important issue, especially during adolescence. Aim: Investigation of the relationship between dietary habits, systematic physical activity and the Body Mass Index (BMI) in adolescents attending high school. Method: A cross-sectional study was conducted between April and May 2010 in a regional urban area, on 80 adolescents, with a mean age of 14.9 years (52.5% boys) who completed a 24-hour recall questionnaire for three nonconsecutive days, and their weight and height were measured. The participants were 3rd year high school pupils who were chosen by cluster sampling (participation 100%). Regularity of eating breakfast, other meals of the day, frequency of junk food consumption and regular physical activity were recorded and their effect on the BMI was examined. Statistical analysis was carried out using the Statistical Package for Social Sciences (SPSS) v. 16.0 for Windows. Results: The only regular meals recorded were lunch for both sexes and dinner for boys, while only 42.9% of boys and 36.8% of girls consumed breakfast on a daily basis. Junk food consumption was significantly greater in boys [t(78)=2.630 p=0.010], and the boys spent more time on physical activities than girls [t(78)=2.291 t=0.025]. Using hierarchical multiple regression analysis, BMI variance was found to be significantly influenced by sports, sex of the pupil and regular consumption of breakfast. Conclusions: Daily consumption of breakfast and physical activity were found correlated with lower BMI in high school pupils. It is considered necessary to educate adolescents in nutritional issues and to investigate the factors associated with their nutritional choices, to ensure that the planning of future interventions will be more effective.