Dietary behaviour of Tehranian adolescents does not accord with their nutritional knowledge.

Objective: To determine the nutritional behaviour of Tehranian adolescents.
Subjects and Methods: This study was undertaken on 7669 adolescents (4070 boys and 3599 girls) of 22 junior high schools and high schools as a representative sample of Tehranian adolescents. A validated knowledge, attitudes and practices (KAP) questionnaire and a food-frequency questionnaire (FFQ) were used. Factor analysis was used to determine the key questions.
Results: The mean ( +/- standard deviation) age and body mass index of the adolescents was 14 +/- 1 years and 27.2 +/- 11 kg m- 2. Although 82% of girls and 75% of boys had good nutritional knowledge, only 25% of boys and 15% of girls had good nutritional practice. Eighty-five per cent of adolescents knew that drinking too many soft beverages resulted in overweight or obesity, but only 4.5% of them did not drink soft beverages. Although 89% of adolescents knew that crisps and corn balls are not healthy snacks, 45% of them used such snacks during their break time. Thirty-seven per cent of adolescents preferred whole-grain biscuits to creamy wafer ones but only 10% of adolescents used whole-grain biscuits as a snack. The most frequently consumed snacks among Tehranian adolescents were sausage sandwiches, cocoa cola, crisps and corn balls, creamy wafers, cakes, chocolate and toffee.
Conclusion: A low percentage of Tehranian adolescents have good nutritional behaviour and in most of them their nutritional practice does not accord with their nutritional knowledge. These results indicate the necessity of nutritional intervention in Tehranian adolescents.