Nutrition and Children'S Physical Health

Proper nutrition is crucial for the appropriate growth and development of children. Undernourished children are at risk for illness, cognitive delay, and poor social skills. Overnourished children are at risk for obesity, diabetes, heart disease, and a shortened life span.

Proper nutrition implies adequate caloric intake for optimal growth and development. At birth, a child's metabolic rate per unit weight is at its peak. This period is coincidental with the highest rate of brain growth and development. Therefore, it is imperative that newborns be adequately nourished. Human breast milk is the ideal food for newborns, and remains the gold standard by which all formulas are measured. Breast-fed infants are healthier, have better cognitive development, and are provided with a more secure mother–infant bond. Research has shown that breast-fed infants are less prone to infection and food allergies, and have IQ scores three to five points higher than their non-breast-fed counterparts. The American Academy of Pediatrics recommends breast-feeding for the first twelve months of life. Solid foods should be introduced around age six months, and supplemented with breast milk. It is recognized, however, that most of the immunologic and cognitive benefits of breast-feeding decrease after the first six months. Thus, the first six months of life provide the greatest return on breast-feeding.

In the newborn period, babies require approximately 100 kilocalories per kilogram of body mass each day. This requirement decreases approximately 10 kilocalories per kilogram every three years, until reaching adult needs of approximately 40 kilocalories per kilogram of lean body mass. It is important to ensure that in addition to adequate energy intake each child has a well-balanced diet to provide appropriate vitamins and minerals as well. The U.S. Department of Agriculture has provided a "food pyramid" as a guide to healthy eating for adults and older children. It suggests that a daily regimen consist of six to eleven servings of bread, rice, cereal, or pasta; two to four servings of fruit; three to five servings of vegetables; two to three servings of dairy products; two to three servings of meat, beans, eggs, or nuts. Sweets and fats are to be consumed sparingly.

Research in the decade 1989–1998 has shown that undernutrition, even in a mild form, can have detrimental effects during childhood, and the younger the child, the more at risk he or she is for undernutrition. It is clear that the greater degree of malnutrition, the worse the outcomes. Inadequate nutrition ranges from the starvation states seen during famines, to the more familiar mild under-nutrition common among children of poor socioeconomic standing. The body, when in a starvation state, preserves vital functions first. Thus, energy is shunted to basic metabolic tasks, leaving little energy for cognitive development and social activity. Two distinct types of starvation are recognized: marasmus, or general caloric insufficiency, and kwashiorkor, or protein deficiency. Marasmus results from inadequate caloric intake. Physically, children with marasmus have a wasted appearance throughout the body. Generally, in the face of inadequate calories, weight is first lost, then vertical growth becomes stunted, and the last growth parameter affected is the head circumference. Although correction of this condition with adequate calories can be achieved, cognitive abilities and height may remain stunted. Kwashiorkor results from inadequate protein intake. The appearance of kwashiorkor is a skinny child with a protuberant belly. This appearance is due to the fatty infiltrate of the liver and water retention of the surrounding tissues. The treatment of this condition is to provide adequate protein. As with marasmus, the damage done while in this state is often not reversible.

Mild to moderate undernutrition is a threat to a child's achieving his or her potential cognitive abilities. Undernourished children are typically easily distracted and fatigued. A 1998 study demonstrated that children who skip breakfast perform worse on tasks of memory and concentration than when they eat breakfast. Other studies have suggested that children with inadequate amounts of protein in the diet had lower achievement scores than their counterparts with adequate protein intake.

Iron deficiency is the most common nutritional deficiency in the United States. Anemia, or decreased red blood cell mass, results from a lack of adequate iron in the body. This lack of iron causes an irreversible decrease in IQ. One of the most common reasons for anemia in toddlers is a crowding out of iron-rich foods by excessive milk intake. In older children, iron deficiency likely results from dietary inadequacies as well as from menstruation in females. Lower socioeconomic classes are at particular risk for iron deficiency.

During the 1990s overnutrition became a concern in industrialized nations. In the United States obesity is the most common preventable health problem affecting both children and adults. Fourteen percent of children and adolescents in the United States were obese in 1999. This represents an increase of 50 percent from the previous decade. Obesity is usually a result of chronic mild overeating, as opposed to repeated binge eating. Consuming five hundred kilocalories more than needed each day will result in a weight gain of approximately one pound per week. Obesity has not only negative psychological effects on the individual, but also negative health effects. People who are obese have shorter life spans, higher than average blood pressure, higher cholesterol levels, increased incidence of diabetes, and more difficulties with the hip and knee joints. Obesity is most effectively treated when interventions are at an early age. Only 25 percent of children who are obese at age six years will go on to be obese adults.

However, 75 percent of obese teenagers will go on to be obese adults. Treatment includes increased exercise, decreased food intake, and family counseling about good food choices. As of the year 2002 there are no safe and effective drug therapies for obese children. Despite millions of dollars spent every year in the weight loss industry, it still appears that the best way to combat obesity is to prevent it.