Testimony by

Dennis Bier, M.D.
Director
Children's Nutrition Research Center

March 4, 1997

Mr. Chairman and members of the Committee, thank you for the invitation to appear before you.

I am the Director of the USDA/ARS Children's Nutrition Research Center (CNRC). I am also a professor of Pediatrics at Baylor College of Medicine. My clinical specialty is pediatric endocrinology with a focus on diabetes, and I came to nutrition research because of the impact of diet on diabetes. I was a member of the Advisory Committee to the Secretaries of Agriculture and Health and Human Services on the 1995 Dietary Guidelines for Americans.

The Children s Nutrition Research Center is one of the ARS human nutrition research centers and is dedicated to understanding the optimal nutritional needs of mothers and their children from conception through adolescence. We are uniquely well-suited to address these issues because, under a cooperative agreement with Baylor College of Medicine and Texas Children s Hospital, Congress has helped create the most complete children s nutrition research facility in the world, housing plant, animal, and medical scientists, and effectively linking basic agricultural research with nutritional investigations in humans.

As part of the ARS, we serve the School Lunch Program and other USDA food assistance programs in an advisory capacity, providing nutritional science information and consultation. I cannot speak to you as an expert on the School Lunch Program itself, or on its funding and policies, but let me make a few comments about the state of current dietary recommendations for school-aged children.

First, let me make it clear that I support the general nutritional recommendations for the School Lunch program since these are consistent with recommendations of the Dietary Guidelines Advisory Committee, and other health and professional organizations, including the American Heart Association, the National Cholesterol Education Program, and the American Academy of Pediatrics Committee on Nutrition.

Secondly, I want to emphasize that, despite the impression you might get by reading the popular press, the nutrition community has agreed for at least 50 years that the principal approach to good nutritional health involves variety, balance, and moderation. All agree further that one should focus on the nutrient content of the diet as a whole and not on individual foods since, per se, there are no good or bad foods.

As long ago as 1959, the noted nutritionist, Dr. Ancel Keys, made the following recommendations: (1) Don't get fat; if you are fat, reduce. (2) Restrict saturated fat. (3) Prefer vegetable oils to solid fats, but keep total fats to under 30% of your total calories. (4) Favor fresh vegetables, fruits, and nonfat milk products. (5) Avoid heavy use of salt and refined sugar. (6) Good diets do not depend on drugs or fancy preparations. (7) Get plenty of exercise and outdoor recreation. (8) Be sensible about cigarettes, alcohol, excitement, and business strain...and do not worry.

These recommendations are remarkably similar to current advice in the Dietary Guidelines for Americans. Further, despite bookstore volumes filled with "magic bullet" approaches to nutritional health, the nutrition community has always emphasized that whole foods, not supplements, are the sine qua non of a healthy diet because foods contain a vast array of both known and as yet unidentified health promoting components that are not present in supplements.

Nutrition-Related Health Problems

The importance of good nutrition is readily apparent. Of the ten leading causes of death in the United States, five -- heart disease, cancer, strokes, diabetes, and atherosclerosis -- have nutritional components, and evidence supports the fact that these nutritional risk factors begin in childhood at a time when eating habits are also being established. Some nutritional antecedents are well-established, for example the relationships between cholesterol and cardiovascular disease, between iron deficiency and poor mental performance, and between childhood obesity and subsequent adult obesity. Other known antecedents are equally compelling - for example, the relationships between poor nutrition education and established childhood eating patterns with the persistence of these patterns into adult life.

The principal nutritional problems of school-aged children are obesity, iron deficiency, inadequate calcium intake, overconsumption of saturated fat and cholesterol, insufficient calorie intake and hunger with associated food insecurity and growth failure, and eating disorders such as anorexia and bulemia.

     The number of overweight children and adolescents in the U.S. has more than doubled in the past decade, from 5% to 11% of children 6 to 17 years old (Troiano, et. al., Arch. Pediatr. Adol. Med., 149:1085-1091,1995), and obese children are more likely than normal weight children to become obese adults (Williams and Kimm, Ann. N.Y. Acad. Sci., 1993).

     Obese children have been found to consume a significantly greater proportion of calories from total fat and saturated fat than non-obese children, placing them at greater risk for developing heart disease later in life (Gazzaniga and Burns, Amer. J. Clin. Nutr., 58:21-28, 1993).

     Data from the Bogalusa Heart Study indicate that children with serum cholesterol levels in the middle and high range showed significantly greater fat intakes than those children within the lowest serum cholesterol category (Nicklas, et. al., J. Adv. Med., 2:451-474, 1989).

     Children ages 5 to 14 years old averaged only about 66% (maximum = 100%) of a Healthy Eating Index designed to provide a single summary measure of diet quality (The Healthy Eating Index, USDA, CNPP-1, 1995).

     Children s dietary intakes of total fat, saturated fat, and sodium are exceeding levels suggested by the Dietary Guidelines for Americans. Adolescent boys also exceed recommended intakes of dietary cholesterol (Kennedy and Goldberg, Nutr. Rev., 53:111-126, 1995).

     Data from the School Nutrition Dietary Assessment Study indicate that school-age children s diets exceed dietary guidelines for fat, saturated fat, and sodium. Based on this study of the daily intakes of approximately 3,350 children enrolled in grades 1 through 12, children averaged 34% of their daily calories from fat, compared with the Dietary Guidelines goal of 30%. Children s diets averaged 13% of calories from saturated fat, compared with the Dietary Guidelines goal of 10%. Average sodium intakes were 4,633 milligrams per day, almost twice as high as the 2,400 milligrams daily recommended by the National Academy of Sciences (Burghardt and Devaney, The School Nutrition Dietary Assessment Study: Summary of Findings, USDA/FCS, 1993).

     Only one in five children consumes the recommended five servings of fruits and vegetables per day, even when credit is given for vegetables in mixed dishes such as pizza or in sandwiches (Krebs-Smith, et. al., Arch. Pediatr. Adolesc. Med., 150:81-86, 1996).

     Children are also not getting enough of some essential nutrients in their diets. Only about 70% of children ages 0 to 5 years and just over 50% of girls ages 12 to 18 years meet the Recommended Dietary Allowance for iron. Only about 2/3 of children ages 0 to 11 years, 50% of boys ages 12 to 18 years, and 40% of girls ages 12 to 18 years meet the Recommended Dietary Allowance for calcium, which is needed to prevent osteoporosis (Kennedy and Goldberg, Nutr. Rev., 53:111-126, 1995). In the long-term, I believe that our approach to optimal childhood nutrition must be two-pronged. First, based on the preponderance of available scientific information, we must apply our current knowledge to improving children s diets today. Second, we must support both basic and applied nutrition research to answer the remaining questions in the future.

Applying Current Nutrition Knowledge

The information necessary for the first approach is provided by the fourth edition of the Dietary Guidelines for Americans, released on January 2, 1996. These Guidelines apply to school age children and urge consuming a varied diet as well as attention to adopting principles of moderation in consumption of fats, sugars, and sodium. The Guidelines do, however, acknowledge that infants and toddlers under the age of 2 have special nutrient needs, and should be fed according to the advice of a health professional. Furthermore, the Guidelines provide special guidance for children in the specific guidelines dealing with body weight and fat intake. These recommendations are based on a solid interpretation of current science.

     The fat guideline recommends that children should gradually adopt a diet that, by about 5 years of age, contains no more than 30 percent of calories from fat.

     The weight guideline emphasizes the need for children to eat healthful diets to promote growth and development at any body weight. It encourages children to eat a variety of foods, including lowfat milk products and other protein-rich foods. The importance of physical activity, rather than food restriction, is emphasized to prevent overweight. Major efforts to change children s eating habits should be discussed with a health professional.

Further, nutrition promotion efforts and improvement of school meals can lead to positive changes in eating habits by exposing children and adolescents to healthful, good-tasting lowfat foods. The Dietary Guidelines for Americans are being incorporated into all USDA food assistance programs, including the School Lunch and School Breakfast Programs. This is important since research has shown that familiarity is a significant factor in developing children s food preferences. As "the appetite grows by what it feeds on", school meals provide an important opportunity to encourage children to learn to enjoy healthful foods (Fisher and Birch, J. Amer. Diet. Assoc., 95:759-764, 1995). In addition, nutrition educators have concluded that programs that use educational methods directed at behavioral change as a goal -- for example, food-based activities and modeling by adults -- are more likely to result in changes in eating behavior than programs which focus only on distribution of information (Contento, et. al., J. Nutr. Educ., 27:277-422, 1995).

Some health professionals have expressed concern that well-meaning parents are unduly restricting their children s food intake, resulting in impairment of growth and development. Others, such a joint working group of the Canadian Pediatric Society and Health Canada, believe that 5 years of age is too young an age to begin limiting dietary fat intake to 30% of calories and, instead, suggest phasing in the fat reduction by the end of linear growth in late puberty. However, research has demonstrated that a diet containing 30% of calories as fat is both safe for ensuring the growth and development of school-aged children and effective in reducing their risk for developing heart disease later in life.

     The Dietary Intervention Study in Children (DISC) is an ongoing randomized controlled clinical trial of diets containing lowered fat, saturated fat, and cholesterol in children. After 3 years in the study, children following diets providing 28% of calories from total fat, less than 8% of calories from saturated fat, and less than 150 mg cholesterol per day were found to have no differences with respect to measures of growth and development than children in a control diet group. Furthermore, blood levels of low-density lipoprotein cholesterol (so-called "bad Cholesterol") decreased significantly in the children on the lower-fat diet as compared to the control group (Lauer, et. al., J. Amer. Med. Assoc., 273:1429-1435, 1995).

     In a just-published study, researchers from Finland report that even very young children can obtain adequate nutrients from a reduced-fat diet. Parents of children 8 months of age were given repeated dietary counseling on fat intake and nutrient intake and their children were followed until they were 4 years old. The children in the intervention group consumed significantly less saturated fat than children in a control group from the age of 13 months onward, but there were no discernible detrimental effects on growth, development, or nutritional adequacy of overall dietary intake. The authors concluded that "individualized dietary counseling that led to clear changes in the type of fat intake had minimal effect on vitamin or mineral intakes." (Lagstrom, et. al., Arch. Pediatr. Adolesc. Med., 151:181-188, 1997)

Importance of Nutrition Research

The second required approach is to support the research necessary to answer remaining questions and provide the needed scientific instructional support for public policy and food assistance programs. The payoff is, admittedly, a long way off but is, nonetheless, a very substantial one both in terms of heath care dollars and in terms of an enhanced quality of life for American adults. For example, we now must make general nutritional recommendations for the entire school-aged population because we do not yet know with high precision which individual children are at risk for the major chronic diseases in adult life. Through the new discoveries in the sciences of genetics and molecular biology, we are now obtaining the tools that will help identify which specific individuals are at high risk for diet-related diseases. Use of this information will allow us to individualize dietary recommendations to those who need them most. Attacking these problems in childhood will pay health dividends to society for many decades, while treating them in adulthood involves much greater expense and a shorter period of benefits.

Similarly, once we can identify specific genotypes responsible disease late in adult life, there is a high likelihood that we will be able to answer important questions about the relationships between childhood dietary intake and the consequences in older adults much more quickly and much less expensively. Currently we must resort to difficult and very, very expensive long-term longitudinal studies in order to address these relationships.

In addition, I'm, sure you have all read about the newly discovered adipose tissue hormones, such as Leptin, that serve to signal the brain about an individual's body fat content and which provoke regulatory responses in the brain that alter food intake and energy expenditure. There is now also evidence that physical activity is another signaling agent in this system. Understanding how circulating chemicals such as leptin induce psychosocial behavioral events in the central nervous system is opening up whole new avenues for understanding the regulation of appetite and satiety. Research is the area is absolutely essential for us to learn how to change a child's responses to food and, therefore, eating behavior when necessary -- as in the case of the overeating which is driving an epidemic of obesity in this country.

Finally, new research tools are now making it possible to design healthier foods of enhanced nutrient composition. For example, one of the research programs at the CNRC is directed toward understanding the mechanisms by which plants store calcium and iron. The goal is to enhance the available amounts of these essential nutrients in plants. Iron deficiency anemia and poor calcium intake are significant problems even in this country, and these inadequacies are critical in many parts of the world where meat and dairy products are not a regular part of the diet.

Further, this research program has also developed the methods of labeling edible plants with stable, non-radioactive isotopes in order to safely and directly measure the absorption and bioavailability of nutrients such as calcium and iron from plant products. Of course, we have many additional programs that address important nutritional issues in children of all ages, from those born prematurely and weighing barely more than one pound to healthy young adults who have just finished puberty, but there is not sufficient time to discuss these in detail.

I thank you for inviting me to testify. It is my hope that the school lunch program can continue to efficiently and effectively meet some of the food needs of our nation's school children, and influence their dietary habits for a healthier long-term lifestyle. I also hope, with your support, that the USDA/ARS Children s Nutrition Research Center at Baylor College of Medicine will continue to be able to provide the basic nutritional science that will help you make the important policy decisions necessary to best feed America s most valuable national resource, its children.