Significant changes in the prevalence of cardiovascular risk factors and nutrition behaviors in children have occurred since the American Heart Association (AHA) last published dietary guidelines for children. Overweight has increased, whereas saturated fat and cholesterol have decreased as a percentage of total caloric intake. New research on the effectiveness of dietary intervention in children has been published, and more attention has been given to the importance of nutrition early in life. In response to these changes, the AHA has released revised nutritional guidelines for children and adolescents, with new focuses on total caloric intake and eating behaviors. The consensus guidelines, which were endorsed by the American Academy of Pediatrics, were published in the September 27, 2005, issue of Circulation (correction appears online at:http://circ.ahajournals.org).
The AHA’s dietary recommendations for persons two years and older stress a diet consisting primarily of fruits and vegetables, whole grains, low-fat and nonfat dairy products, beans, fish, and lean meat. Table 1 provides daily estimated calorie and serving recommendations by age. Calorie estimates for children three years and older are based on a sedentary lifestyle; children and adolescents who are more physically active will require more calories. Table 2 provides daily recommended intakes of fiber, sodium, and potassium.
The new guidelines allow a more liberal intake of unsaturated fat than in the past and focus on ensuring adequate intake of omega-3 fatty acids. Because the major sources of saturated fat and cholesterol in children’s diets are fatty meats and full-fat milk and cheese, the use of low-fat dairy products and lean cuts of meat in appropriate portion sizes is critical in meeting nutrient requirements.
Children and adolescents often consume inadequate amounts of fish. However, the AHA advocates consumption of a variety of fish and shellfish (two servings weekly). Recent evidence suggests that commercially fried fish products do not provide the same benefits as other sources of fish because they are relatively low in omega-3 fatty acids and high in trans-fatty acids. The consumption of shark, swordfish, king mackerel, and tilefish should be avoided in young children because of the high levels of mercury that may be present in these fish. Five of the most commonly eaten varieties of fish are low in mercury: shrimp, canned light tuna, salmon, pollack, and catfish.
The increase in obesity rates in the United States has emphasized the need to match appropriate caloric intake to energy expenditure. One approach is the concept of discretionary calories. Total caloric intake is the sum of essential calories (i.e., caloric intake necessary to meet recommended nutrient intakes) and discretionary calories (i.e., additional caloric intake needed to meet energy demands and for normal growth). There is a significant difference in the discretionary calorie allowance among sedentary, moderately active, and active children, with more physically active children requiring more energy from food to maintain normal growth. The amount of discretionary calories in the recommended daily intake for young, sedentary children is less than the amount of calories provided by a typical portion size of most low–nutrient-dense snacks and beverages. Consuming diets that include primarily nutrient-dense forms of the foods listed in Table 1, participating in regular moderate to vigorous physical activity most days of the week for at least one hour per day, and limiting the amount of time spent watching television and playing video games to less than two hours per day will help children accomplish the goal of balancing energy intake and expenditure.
The gap between current dietary practices and recommended diets for infants, children, and adolescents is significant. Population-based data have been used to identify specific problem areas: total caloric intake, eating patterns, balance of foods and beverages chosen from each food group, and intake of specific nutrients.
Approximately 76 percent of mothers initiate breast-feeding. However, the proportion of mothers who continue to breastfeed for the infant’s first four to six months of life is significantly lower. Only 4 percent of infants participating in the Special Supplemental Nutrition Program for Women, Infants, and Children, and only 17 percent of nonparticipants, remain exclusively breastfed by six months of age. This suggests a strong socioeconomic status gradient in breastfeeding behavior. By four to six months of age, 66 percent of infants have received grain products, 40 percent have received vegetables, 42 percent have received fruits, 14 percent have received meat, and 0.6 percent have received sweetened beverages. By nine to 11 months of age, 98 percent of infants have received grain products, 73 percent have received vegetables, 76 percent have received fruits, 79 percent have received meat, and 11 percent have received sweetened beverages. Sweetened beverages are consumed by 28 percent of children 12 to 14 months of age, 37 percent of children 15 to 18 months of age, and 44 percent of children 19 to 24 months of age.
During the transition from a milk-based diet to adult foods, the types of vegetables consumed change adversely. Deep yellow vegetables are consumed by 39 percent of children at seven to eight months of age and by 13 percent of children 19 to 24 months of age; french fries are the most commonly consumed vegetable in children 19 to 24 months of age. Similarly, fruit consumption declines to the point that one third of children 19 to 24 months of age consume no fruit, whereas 60 percent consume baked desserts, 20 percent consume candy, and 44 percent consume sweetened beverages.
Significant adverse changes have occurred in older children’s food consumption as well. These changes include a reduction in regular breakfast consumption, an increase in the consumption of foods prepared away from home, an increase in the percentage of daily calories consumed from snacks, an increase in consumption of fried and nutrient-poor foods, a significant increase in portion size at each meal, and an increase in consumption of sweetened beverages. The shift in dietary patterns has resulted in median intakes of micronutrients falling below the recommended values during adolescence. Sodium intake is far in excess of recommended levels, whereas calcium and potassium intakes are below recommended levels.
Implementation of Dietary Recommendations
Family and cultural considerations must be addressed when making dietary recommendations for children and adolescents. Most meals are consumed outside the home; sources of nourishment include schools, child-care and after-school youth programs, restaurants, vending machines, convenience stores, workplaces, and packaged foods designed for minimal preparation time.
Adult influences are important with regard to childhood nutrition; consumption of a healthful diet by persons who supervise children improves the quality of the children’s diets. Caregivers should control which foods are available and when they can be eaten, as well as provide social context for eating behaviors (e.g., family meals, role of food in social situations) and counteract inaccurate nutritional information in the media and other sources of misinformation. Parents should teach children about food and nutrition at the grocery store and when cooking meals, and they should instruct caregivers about which kinds of foods their children should eat.
CONCEPTION TO TWO YEARS OF AGE
It is important for current and expectant parents to maintain a healthy weight. Children whose mothers are obese early in pregnancy are more likely to be overweight as young children; a similar effect has been noted in children whose parents are obese or become obese during their childhood. Excessive maternal weight gain during pregnancy is associated with a two- to threefold increased risk that the mother will be overweight after the pregnancy. This may increase her child’s risk of obesity, impaired glucose tolerance, impaired insulin secretion, and type 2 diabetes during adolescence.
There is conflicting evidence on the relationship between breastfeeding and a child’s future risk of cardiovascular disease and obesity. Several studies have suggested that breastfeeding leads to lower blood pressure later in childhood. Although breastfeeding is associated with higher blood cholesterol levels at one year of age, it also may result in lower levels later in life. Rapid weight gain during the first four to six months of life is associated with future risk of overweight; studies suggest that partially breastfed and formula-fed infants consume 20 percent more calories per day than do infants who are exclusively breastfed. Physicians should identify infants who are gaining weight rapidly and those whose weight-to-length measurement exceeds the 95th percentile, and they should help correct overfeeding if necessary.
Amniotic fluid and breast milk provide flavor exposure to the fetus and infant. These exposures influence taste preference and food choices after weaning. Thus, exposure to healthier foods through maternal food consumption during pregnancy and lactation may improve acceptance of healthy foods after weaning. Because infant responses to taste are different than mature taste, these early exposures may be critical in determining food preferences later in life.
The period from weaning to consumption of a mature diet (i.e., three months to two years of age) represents a radical shift in an infant’s pattern of food consumption, but there has been little research on the best methods to achieve optimal nutritional intakes during this transition. Transition to other sources of nutrients should begin at approximately four months of age to ensure sufficient micronutrients in the diet. Parents should delay the introduction of undiluted juice until at least six months of age and limit the amount consumed to no more than 4 to 6 ounces per day. Parents also should respond to satiety clues and not overfeed; infants and young children usually can self-regulate total caloric intake. Children should not be forced to finish meals if they are not hungry. Parents should introduce healthy foods and continue to offer them if the child initially refuses the foods.
TWO TO SIX YEARS OF AGE
Dietary recommendations for children two to six years of age are similar to those for older persons. Challenges relate to providing quality nutrient intake and avoiding excess caloric intake. Dairy products are a major source of saturated fat and cholesterol in this age group; a transition to low-fat dairy products is recommended. Sweetened beverages and other sugar-containing snacks are major sources of caloric intake. Parents should be reminded that they are responsible for choosing the foods that their child eats and deciding when and where they are eaten. The child should be responsible for deciding whether he or she wants to eat and how much. Two natural parental impulses, pressuring children to eat and restricting access to specific foods, are not recommended because they often lead to overeating, dislikes, and paradoxical interest in forbidden foods.
SIX YEARS AND OLDER
As children grow up, sources of food and influences on eating behavior increase. Social constraints on families may necessitate the presence of multiple caregivers, eating out, and frequent fast-food consumption. Many children are home alone while their parents are at work, and they must prepare their own snacks and meals. By early adolescence, fad diets may be initiated. Meals and snacks routinely are obtained outside the home, often without supervision. Sweetened beverages and naturally sweet beverages such as fruit juice often contribute to excessive consumption of discretionary calories and supplant the intake of foods containing essential nutrients. Consumption of sweetened beverages should be limited to 8 to 12 ounces per day.
During adolescence, amplified caloric and nutrition needs resulting from pubertal growth stimulate appetite. The combination of centrally driven appetite stimulation and an increasingly sedentary lifestyle augments obesity. Peer pressure, partly driven by media promotion of fast-food, makes overeating seem acceptable. These changes in eating patterns result in consumption of excess fat, saturated fat,trans-fats, and added sugars and insufficient consumption of micronutrients such as calcium, iron, zinc, and potassium, as well as vitamins A, D, and C and folic acid.
Counseling of older children and adolescents must be individualized to accommodate the range of contemporary lifestyles; less success is achieved in older children. Parental role modeling is important in establishing children’s food choices.