Normally, the energy requirements of adolescents tend to parallel their growth rate, and individuals meet their energy needs by means of their appetite with adequate precision. As a result, the majority of adolescents maintain energy balance, and a varied food intake provides sufficient nutrients to ensure optimal growth and development.
Stress and emotional upsets however can seriously affect the
energy balance in adolescents, resulting in the consumption of too little or
too much food. Mild or severe infections, nervousness, menstrual, dental or
skin problems (acne) can result in alterations of appetite, and those
adolescents on marginal diets are the most vulnerable. Emotional stress is
often associated with food faddism and slimming trends, both of which can lead
to eating disorders such as anorexia nervosa.
On the other hand, the prevalence of overweight
and obesity in children and adolescents is now a major nutritional
problem and the condition is likely to persist into adulthood. Developing
adolescents are particularly concerned about their body image and excessive
weight can have profound effects on their emotional well being as well as on
their physical health. The cause of obesity is multifactorial and
socio-economic, biochemical, genetic, and psychological factors all closely
interact.
Lack of activity plays an important role in the development,
progression and perpetuation of obesity in adolescence. Surveys of young people
have found that the majority is largely inactive and health professionals and
governments are now encouraging higher levels of physical activity among
children and adolescents. Physical inactivity does not only have a prime role
in the development of overweight and obesity, but also on the development of
chronic diseases such as heart disease, certain cancers, diabetes,
hypertension, bowel problems and osteoporosis in later life. In addition,
physical activity is related to improvements in body flexibility, balance,
agility and co-ordination and strengthening of bones. The current
recommendation is for children to try to be physically active for at least 60
minutes daily.