Читать книгу Eating for Sport - Shelly Meltzer - Страница 28

In recent years, children’s participation in high-level sports has become increasingly prevalent. If energy and nutrient intakes are not adequate to support the intense training, then growth and maturation may be delayed. In teenage girls menarche (onset of menstruation) may be delayed, which is a risk factor for menstrual dysfunction resulting in low peak bone density (see pp75–76). This is of great concern in aesthetic sports like gymnastics and ballet, where young athletes may severely restrict their energy intake to achieve lower body weights. In boys and girls total catch-up growth may be compromised if the delay in maturation is severe. In addition, immature bones are more susceptible to stress injuries.

The dietary needs and challenges of children and adolescents differ from those of adults. Fluid, for example, is a specific challenge for children because they do not tolerate extreme temperatures well and produce less sweat. Teenagers, especially those participating in competitive sport, are faced with additional challenges that include sexual maturation, change in body composition, rapid growth, coach, parent and peer pressure, scholastic achievement and social acceptance. In the pre-pubertal period the proportion of fat and muscle in girls and boys tends to be similar, with body fat being about 19 and 15% respectively. However, during puberty girls gain more body fat than boys (due to the laying down of energy reserves for pregnancy and lactation), whereas boys gain twice as much muscle mass. This causes a lot of distress among many teenaged girls resulting in distorted body images, dieting and, in some cases, the development of eating disorders. Male teenagers on the other hand want to look more masculine and may use nutritional supplements to achieve this (see p98).

Children and teenagers require adequate energy and nutrients to support normal growth and development and the increased needs of training.

A multi-disciplinary approach involving parent, coach, young athlete and sports physician/dietitian with ongoing monitoring will help the early detection of any problems and establish lifelong healthy habits. Monitoring may involve measuring height, weight, skinfolds (see pp126, 127), pubertal stage, bone age, nutritional status, symptoms of eating disorders, and measures of body image.