It is the period of transition from childhood to adulthood. During this period there is accelerated physical, biochemical and emotional development.
Adolescents are physically more active and have a greater metabolic rate.
The final growth spurt occurs during this period. Many changes take place in the body like physical and sexual growth due to the influence of different hormones. This may be due to increased requirements or may just be a form of socializing. The snacks teenagers eat are often full of fats, carbohydrates and sugar. Some of them try to use food as a way to establish their identity, perhaps by over eating or going on a crash diet.