Many major risk factors for disease in developed countries (that is, blood pressure, cholesterol, overweight, obesity, low fruit and vegetable intake, and iron deficiency) are nutrition related. A nutritionally balanced diet for school aged children will enhance learning capacity as well as prevent adult diseases such as ischemic heart disease, hypertension, some types of cancer and diabetes. In principle therefore, nutritional problems in the school aged child may carry into adulthood. Our society’s propensity to gravitate toward convenient, convenience foods which tend to have high fat content are a major determinant in our nutritional problems. Some of the nutritional problems in this age group include the following:

Obesity

There is an increasing trend of being overweight and obese in school-aged children, mainly attributable to reduced physical activity. Focus on reducing obesity and improving diet and physical activity is therefore a priority in many countries. Obesity is a nutritional disorder and is a major risk factor for cardiovascular disease in adulthood. Obesity is also implicated in the development of insulin resistance limiting the body’s ability to absorb glucose. Studies indicate that children have too much fat in their diets. Eating diets high in fat and being less physically active leads to positive energy balance which may be a predisposition to lifelong health problems (for example, hyperglycemia  cardiovascular problems, type 2 diabetes and obesity) in older adult years.

Eating Disorders

An increasing number of cases of anorexia and bulimia are being more and more associated with this age group. Lured by media propaganda and other social pressures, some children feel pressure to be extremely thin. This extreme measure of weight control is achieved by restricting food intake.

Blood cholesterol levels

To reduce risk of heart disease, children should form habits related to healthy eating and exercise early in life including the following:

• Consume a variety of food that is nutritionally adequate.
• Consume enough calories to support growth and development, and to reach or maintain desirable body weight.

Tooth Decay

Cavities are caused by over indulging in sugary foods such as soft drinks and confectionery may predispose school aged children to poor dental health. The risk of tooth decay is greatest with the consumption of large amounts of sticky sugary and starchy foods that stick to the teeth (sweets, sodas and candy).

Anemia

Iron-deficiency anemia may develop in children whose diet is iron-deficient. Iron is an oxygen-carrying component of blood. Anemia in school-aged children may result in deteriorating effects including, lower school achievement due to impaired cognitive development, poor attention rate and general fatigue. A study involving 5398 children between the ages of 6 and 16 in the United States, found that lower standardized math test scores were found among those with iron deficiency. Children deficient in iron were twice as likely to score below average on math tests; this finding was more pronounced among girls.

Reference
http://www.virtualmedicalcentre.com/healthandlifestyle/nutrition-for-school-children/89