Type 2 diabetes in children is intimately tied to obesity.1 Approximately 85% of children with type 2 diabetes are overweight or obese at diagnosis.2 The prevalence of type 2 diabetes in children in the United States is estimated at 1.8 per 1,000,3 and the increasing incidence of this disease in children appears to be tracking along with the obesity epidemic.
Results from the 1999-2002 National Health and Nutrition Examination Survey (NHANES) indicate that an estimated 31% of children between ages 6 and 19 are at risk for overweight, and 16% of children and adolescents are classified as overweight.4 Not surprisingly, many efforts toward the prevention and treatment of type 2 diabetes are centered on education and lifestyle changes for treating overweight. The nutritional management of the overweight child parallels that of the child with type 2 diabetes.
IDENTIFICATION OF EXCESS WEIGHT IN CHILDREN
In adults, an absolute body mass index (BMI) value is used to identify overweight and obesity. BMI is defined as weight in kilograms divided by height in meters squared. An adult with a BMI value between 25 and 30 is classified as overweight; above 30 as obese.
According to the Centers for Disease Control and Prevention, the term "overweight" should be used in place of "obese" when screening children and adolescents. In children, the extent of overweight is assessed using percentiles on a BMI growth chart versus absolute BMI values. Children who are between the 85th and 95th percentile for BMI are classified as "at risk for overweight" Children who are above the 95th percentile for BMI are classified as "overweight" BMI and other growth charts can be downloaded and printed from the CDC Web site (http:// www.cdc.gov/growthcharts).
Figure.Weight loss or maintenance recommendations in children at riskfor overweight (85th to 94 th percentile) or overweight (95th percentile or above) based on age.
In obese children, symptoms of prediabetes such as insulin resistance and impaired glucose tolerance are correlated with visceral adiposity, perhaps due to abnormalities in insulin signaling in the presence of larger intramyocellular lipid levels.5 Waist circumference and skinfold measurements can offer valuable information on the extent and location of body fat and serve as a valuable tool for measuring gradual changes in adiposity that weight alone may not identify. Waist circumference tables are available for reference,6 as are tables for comparing skinfold measurements across age and gender7 groups; however, to better assess the effects of treatment, it is best to compare measurements against the child's own baseline values.
The American Diabetes Association Position Statement on the treatment of diabetes and prevention of related complications states that the goal of medical nutrition therapy in children with type 2 diabetes is to "facilitate changes in eating and physical activity habits that reduce insulin resistance and improve metabolic status."8 The goal of treatment for the child with type 2 diabetes includes the cessation of excessive weight gain with normal linear growth,2 normalization of fasting blood glucose values, and a near-normal level of hemoglobin A1C. The goal of medical nutrition therapy (MNT) for those at risk for diabetes is to encourage physical activity and promote food choices that induce moderate weight loss or prevent weight gain.8
In adults with type 2 diabetes, a modest reduction in weight (10% to 15%) can lead to a drop in blood insulin levels and improved insulin sensitivity.9 While the extent of weight loss needed to decrease insulin resistance in children with type 2 diabetes is not clear, insulin sensitivity has been found to improve with weight loss in overweight children.10 However, weight maintenance in the setting of normal linear growth versus weight loss is often the goal in treating overweight children, unless in the presence of severe obesity or secondary complications (such as hypertension, dyslipidemias, sleep apnea or orthopedic problems).11 The Figure (see page 702) outlines the recommendations for weight goals based on the child's overweight status and the presence of complications.
Families should first demonstrate that they can maintain the child's weight. After success of weight maintenance, further discussion should be placed on gradual weight loss to reach a BMI goal at or below the 85th percentile. The weight loss goal given to adults of 1 to 2 pounds per week is unrealistic for children and puts undue pressure on both the child and the family. A weight loss rate of about 1 pound per month is realistic for children with normal linear growth. An example is illustrated in Table 1: a 13-year-old boy who loses 1 pound per month and grows at a normal linear rate will decrease his BMI from the 95th percentile to the 83rd percentile in approximately 9 months.
ASSESSMENT OF NUTRITION AND PHYSICAL ACTIVITY
A global assessment of eating and activity patterns can help identify specific lifestyle behaviors that lead to excess caloric intake and weight gain. Sidebar 1 (see page 704) outlines basic areas to consider in this assessment. Referral to a clinical dietitian who specializes in pediatrics is recommended for more specific assessment and goal setting.
GOAL SETTING AND GENERAL TREATMENT
A team approach often is most effective in treating overweight children with diabetes. The healthcare team should include not only a physician or nurse practitioner but also a nutritionist, a mental health provider, and, if possible, an exercise physiologist. In some instances, it may be best to refer the patient to an obesity specialist or program if it is not feasible to provide these services.
Reduction of BMI in a 13-year-old Boy With Normal Growth Rate and Weight Loss of 1 Pound Per Month
Because a child's eating patterns are influenced by the family's lifestyle and eating habits, treatment should not be limited to the child but should include goal setting for the family and other caregivers. Likewise, children who are overweight may have a parent or siblings with weight issues, so a focus on improving the entire family's nutrition and activity habits may be well received. Studies have shown that a family approach to the treatment of overweight is most effective in achieving results.12 In diabetes management, children whose parents remain intimately involved with diabetes care and adjust the dietary habits of the entire family seem to experience better glycemic control.13
When developing lifestyle recommendations for the child and the family, the following serve as useful goals:11
* Increase the family's awareness of how current eating and activity patterns affect the child's weight and diabetes control.
* Identify behaviors that need to be changed.
* Modify current behavior to promote healthy eating and increased activity.
* Reinforce the concept of making one to three small changes at a time that, when applied consistently, can lead to permanent new behaviors.
* Encourage the family to be cognizant of behaviors and to recognize problems in their changing environment to prevent a return to previous habits.
Because treatment often is focused on changing behaviors and habits, the visits may need to be frequent, even if brief. A timeline of every 2 to 4 weeks allows the family to implement changes and maintain motivation.
The overall goal in dietary management of the overweight child with type 2 diabetes is to reduce caloric intake as energy expenditure is increased. The approach to achieving this goal may simply be to incorporate more whole grains, fruits, and vegetables and lean proteins while gradually reducing processed and high-fat foods.
The practice of carbohydrate counting often is employed in the management of type 1 diabetes because insulin is titrated to carbohydrate intake. However, in children with type 2 diabetes, this is not usually the first method of dietary treatment because the primary focus is improving overall diet quality and incorporating healthier lifestyle changes.
Meal planning, in which the patient is offered recommendations for the number of servings to consume from the different food groups, has been the traditional method for providing structure and variety in meals and for regulating caloric intake. However, the focus in dietary treatment of type 2 diabetes has moved toward a more individualized approach in which dietary habits are changed gradually to achieve long-term goals. While the use of meal plans is still an option for the practitioner, families should be cautioned not to perceive the meal plan as a "diet" that is followed for short periods of time without long-term adaptation. Meal plans also are not always easy to follow on a long-term basis and may place too much focus on the child while detracting from the importance of familial changes in eating and activity patterns.
Motivational interviewing, a patientcentered counseling approach in which the patient is allowed to evaluate the pros and cons of suggested behavioral change and develop individual goals toward change, has become an increasingly popular approach to behavior modification.14
While this counseling technique has been employed primarily for the treatment of substance abuse, there is some evidence that it may also be successful in changing health behaviors.15
In motivational interviewing, the patient may be asked to rate a particular problem on a scale from 1 to 10 and then to expand on the reasons that rating was chosen. Depending on the readiness for change, the child or family may be given more information to raise awareness or to improve motivation toward change or, if the patient is ready for new behaviors, goals can be negotiated to begin lifestyle changes.15
Regardless of the method used in counseling, goals should be small, measurable, and achievable and should include the input of the child and the family. For example, the initial clinic session may focus simply on conducting a thorough assessment of the child's and family's eating and physical activity habits, building rapport, and, if the family is ready for change, helping to develop one to three goals to be tried before the next clinic visit In follow-up sessions, the practitioner may offer guidance in either developing previous goals or creating new ones.
Examples of small, measurable and achievable goals include:
* Decreasing or discontinuing high-caloric beverages, such as soft drinks and natural or artificial juices, and replacing them with water or caloriefree beverages;
* Reducing the frequency of eating out occasions (eg, from four times per month to two times per month);
* Adding a fruit or vegetable to breakfast, lunch, or dinner;
* Lowering the portion size of food by ¼ to ½ cup.
* Reducing the number of snacks kept in the home to only three types of snacks and increasing the variety of fresh fruits and vegetables; and
* Substituting fruit whole-grain crackers, or baked chips for processed snacks (eg, chips, candy, high-fat crackers).
Acceptable Daily Intake (ADI) Levels of Artificial Sweeteners for Children
Dietary Reference Intakes for Acceptable Macronutrient Distribution Ranges16
According to the Institute of Medicine's Food and Nutrition Board's Dietary Reference Intakes, the distribution of total calories from carbohydrates should be about 45% to 65% for all children.16 In terms of glycemic response, the total amount of carbohydrates may play a larger role than the type of carbohydrate,16 but for weight loss, it is recognized that emphasis should be placed on promoting whole grains, fresh fruits, and vegetables as alternatives to processed grains and fruit juices. The Dietary Guidelines for Americans 200517 emphasizes the incorporation of five to nine servings of fruits and vegetables and at least 3 ounces of whole grains per day. For children older than 4, a serving of vegetable is about ½ cup cooked or 1 cup raw. A serving of fruit is one small (4-ounce) fresh fruit or ½ cup of cut fruit.
Caloric and noncaloric sweeteners can have a place in the diet of the child with type 2 diabetes. Sucrose and other caloric sweeteners (eg, honey, corn syrup) can be included in the diet,8 but these added sugars should not exceed 25% of total calories.16 Parents should be made aware that foods high in added sugars are also often high in fat and can contribute to excess calories. Sugar alcohols such as mannitol, sorbitol, and xylitol contain one-third to one-half the calories of sucrose. However, foods containing sugar alcohols are not necessary if dietary recommendations are geared towards more natural or healthier foods and smaller portions of high-calorie foods. Caution should be taken with extensive use of sugar alcohols, as they can lead to gastrointestinal discomfort.
Sweetened or calorie-containing beverages, with the exception of milk, can be substituted by either water or beverages made from noncaloric sweeteners, such as saccharin, aspartame, acesulfame-K, and sucralose. The Food and Drug Administration (FDA) has established an Acceptable Daily Intake (ADI) for aspartame, acesulfame-K and sucralose, which includes a 100-fold safety factor.18 The World Health Organization's Joint Expert Committee of Food Additives has set the ADI for saccharin (Table 2, see page 705).18
Fiber goals are not higher in children with diabetes; however, higher fiber intake may help with satiation and satiety and lead to a decrease in caloric intake. 19 Fiber intake should be increased gradually to achieve the Dietary Reference Intakes (Table 3, see page 705).
Glycemic index is defined as the area of the blood glucose response curve after the consumption of 50 grams of carbohydrate from a test food divided by the area under the curve after the consumption of 50 grams of carbohydrate of a control food (white bread or glucose).20 Glycemic index is influenced by a number of factors, including carbohydrate type, fiber content, protein, fat, method of processing, and preparation.
At this time, there is insufficient evidence of the long-term benefits of following a low glycémie index diet.21 However, the glycémie index can be used as a tool to reinforce the concept of selecting more whole grains, fresh fruits, vegetables, lean proteins, and healthy fats.
Protein intake generally is adequate or even high in children. In the US, children and adolescents ages 6 to 19 consume an average of 70 to 90 grams of protein per day,22 which exceeds the Dietary Reference Intake recommendations for protein (Table 3).
Children with diabetes do not need to consume greater than the Dietary Reference Intake amount for protein. Protein does not appear to increase plasma glucose concentrations, nor does it slow down the peak glucose response,8 but protein-rich foods often also are high in fat, which can slow down the glucose response. Nutritional recommendations should focus on substituting high-fat protein sources with lean meats (chicken, fish, turkey, pork), low-fat milk, and vegetable proteins.
Recent literature suggests that a protein-sparing modified diet may be applied in severely overweight children with type 2 diabetes. However, careful monitoring by a healthcare team is absolutely necessary to prevent metabolic complications.23
One method for lowering caloric intake is to reduce total dietary fat. Total fat intake should be kept around 30% to 40% of calories for children ages 1 to 3 and 25% to 35% of total calories for children 4 or older.16 Because patients with diabetes are at higher risk for cardiovascular disease, the primary goal is to educate families on choosing foods higher in polyunsaturated and monounsaturated fats and lower in saturated fat, cholesterol, and trans fatty acids.
Trans fats, primarily found in processed foods containing hydrogenated fat, appear to affect lipid levels and could adversely affect glucose metabolism and insulin resistance.24 As of January 2006, food manufacturers will be required to list the grams of trans fat on the Nutrition Facts food label.25 Many snacks, particularly single-portion snacks (eg, crackers, cookies, granóla bars, potato chips), may be chosen for convenience but often are high in saturated fat, trans fats, and calories and should be limited or replaced with healthier options.
As a general guideline, a healthy snack is low-fat, with less than 3 grams of fat per reference serving; 15 to 25 grams of carbohydrates; 50 to 150 calories per reference serving; naturally colorful; rich in vitamins and minerals; low in trans fatty acids and saturated fat; and appealing and fun to eat. A list of snacks that fit these criteria is provided in Sidebar 2 (see page 707).
Omega-3 fatty acids can lower plasma triglycerides in people with type 2 diabetes.26 The American Heart Association recommends the consumption of fish twice a week, but children should limit the amount of shark, swordfish, king mackerel, and tile fish (also known as golden bass or golden snapper), as these fish are high in mercury.
FOODAWAY FROM HOME
Consumption of food away from home has increased significantly for children in the past 30 years, from about 6.5% of total calories in the late 1970s to about 19% in the late 1990s.27 A recent study of a national sample of children in the US found that about 30% reported consuming fast food on any given day. Not surprisingly, those who consumed fast food were more likely to have higher intakes of calories, total fat and saturated fat, and sugar-sweetened beverages, while fruit, vegetable, and milk intake was lower.28
Frequent consumption of food away from home places the child at risk for weight gain and potentially for type 2 diabetes. In a study of fast food consumption during a 15-year period, those who visited fast food establishments more than twice weekly gained an extra 4.5 kg of body weight and had a twofold greater increase in insulin resistance.29
Nutrition therapy should include guidance on the frequency and selection of food consumed away from home. However, realistic expectations should be set that take into consideration financial and other restrictions that lead to reliance on fast food, such as lack of time or poor knowledge of food preparation. A family that frequents fast food establishments three or four times per week, for example, can be offered suggestions on how to reduce the frequency of visits to once or twice a week, then once a week, then once every 2 weeks, etc., so the habit is reduced slowly as information is provided on foods that can be prepared at home.
In addition, guidance can be offered on appropriate food choices when dining outside the home or ordering in. For example, families could be advised to skip appetizers or the bread bowl, to share meals, to order less food, and to avoid sweetened beverages.
Mamteining a food and activity log periodically may help the child and family identify areas that need to be improved and help reinforce positive behavior changes. The log simply provides data for developing goals and should not be used to pass judgment on present lifestyle habits.
An increase in physical activity is crucial for achieving long-term weight goals and for glycémie control in diabetes. The Dietary Guidelines for Americans 2005 suggests that children receive at least 60 minutes of activity on most, preferably all, days of the week.17 Recommendations for increasing physical activity should be titrated and advanced slowly based on the age and physical ability of the child or adolescent.
One initial goal may be simply to decrease sedentary time,11,30 which can be initiated by limiting the time spent watching television or using other entertainment media. A simple rule used in practice is to suggest that the child spend less than 30 minutes at a time on sedentary activity. The child is instructed to begin a more physically engaging activity after 30 minutes of sedentary time, whether it be simply standing up and walking around or doing a chore or engaging in unstructured play. The child can be helped to develop a list of activities that can be done in the afternoon before homework is started or immediately after school. Likewise, a list of "distractions" can be created to help the child find alternatives to snacking in the afternoons. This approach, however, is more effective with adult supervision and encouragement.
Young children who are overweight or at risk for overweight can be encouraged to increase physical activity by way of frequent unstructured play. The home environment can be altered to include more opportunities for play and fewer opportunities for sedentary activities. Older children (for example, older than 7) may benefit from more structured activities, such as team sports, swimming, and dance classes.
However, special attention should be placed on the child's level of overweight because weight-bearing activities, such as running, brisk walking, and field sports, may place undue stress on bones and knees. In an article on exercise treatment in obesity, Sothern suggests several structured exercise guidelines that consider overweight status.31
* Children at risk for overweight (BMI between the 85th and 95th percentile) should engage in weight-bearing activities such as walking, exercise machines (treadmill or stair climber), field sports, roller blading, hiking, racquetball or tennis, martial arts, jumping rope, indoor gym sports, swimming, dancing, playing tag.
* Overweight children (BMI at the 95th percentile or above) should engage primarily in nonweight-bearing activities such as swimming, cycling, strength training, and short walks with lots of opportunity for rest.31
* Children who are above the 97th percentile for BMI may need weekly supervision by a trained exercise professional and should engage in only nonweight-bearing exercise until BMI drops closer to the 95th percentile.
In light of the strong association between excess weight and type 2 diabetes, the nutritional management of the child with type 2 diabetes often focuses on changing dietary and physical activity habits to normalize weight, instill long-term healthy habits, and provide glycémie control. A multidisciplinary approach to the treatment of childhood obesity should include the child's family and caregivers to be most effective. Weight goals in children should be based on the age of the child, the extent of overweight, and the presence of complications. Likewise, physical activity is an important component of treatment and should be titrated to the child's age, ability and overweight status. Efforts to avoid the development of obesity, and potentially type 2 diabetes, should be started early in the child's life. Education and fostering a healthy lifestyle during childhood is the best defense to slow down or reverse the obesity epidemic in our society that is now affecting even the youngest of children, setting them up for potentially life-threatening diseases in the future.
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1 8. Position of the American Dietetic Association: Use of Nutritive and Nonnutritive Sweeteners. JAm Diet Assoc. 2004;104(2):255-275.
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Reduction of BMI in a 13-year-old Boy With Normal Growth Rate and Weight Loss of 1 Pound Per Month
Acceptable Daily Intake (ADI) Levels of Artificial Sweeteners for Children
Dietary Reference Intakes for Acceptable Macronutrient Distribution Ranges16