Summary 1 – 3

their intake requirements represent a tiny fraction of dietary energy intake. Despite this, fat is an important dietary component in childhood because it serves both as a vehicle for absorption of fat-soluble vitamins and as a dense source of energy for metabolic processes and growth. In addition, diets that are inordinately low in fat are also responsible, indirectly at least, for impaired immune function that accompanies energy deficiency in childhood. As detailed by Butte (1) at this symposium, the energy cost of growth is a very small fraction of total daily energy expenditure after the first year of life. Nonetheless, growth failure is one of the most sensitive indicators of energy deficiency in children. In fact, impaired growth is often used to index the lower limits of adequate fat and energy intakes, and reports of growth failure in small numbers of children consuming low-fat diets have led to widespread concerns about limiting the fat intakes of children (2, 3). Data presented at this symposium on children from Japan, Chile, and mainland China with fat intakes < 22% of total energy confirmed the consequential growth failure. The correlation between impaired growth and percentage of total energy from fat is not perfect. Fourto 14-y-old vegetarian Chinese children from Hong Kong grew within the normal range while consuming diets that contained an average of 23% of energy from fat. Nevertheless, also presented at this symposium were the results of 2 large, well-controlled clinical trials conducted in a total of >1700 children in developed countries. These investigations, the Special Turku Coronary Risk Factor Intervention Project (STRIP) for babies (4–6) and the Dietary Intervention in Children (DISC) study (7, 8), clearly showed that growth, development, and macronutrient intakes are not compromised in children consuming 27–30% of dietary energy as fat. These conclusions are now well supported by the results of systematic studies reported by other investigators (9–14), including data from China and Japan presented at this symposium by Chunming (15), Leung et al (16), and Murata (17). Importantly, the STRIP study recruited infants <1 y of age and showed that essential fatty acid adequacy and fatsoluble vitamin requirements can be met in the weaning and toddler age groups with reduced-fat diets in the range of 27–30% energy. This conclusion is also supported by the observation that dietary fat intake in healthy weaning infants is often ≤30% (8). Further, Prentice and Paul (18) presented data from doubly labeled water studies of energy expenditure in children living in developing countries, which also support the position that diets commonly low in fat and energy in these countries are sufficient to support growth in healthy children. However, these diets are inadequate for supporting catch-up growth after episodes of diarrhea and other infections. Low-energy-density weaning foods appear to be the major contributor of growth failure in this context. Because dietary fat needs appear to increase when children are subjected to environmental stresses, especially the stress of infection, symposium participants recommended that new indexes of dietary fat inadequacy (eg, immunologic responses to appropriate challenges) be developed and tested. Overall, however, symposium participants were unable to reach a consensus on the lower limit of fat intake in children that is compatible with adequate growth and development. In addition, they were unable to agree on the range of optimal fat intake in childhood. Nevertheless, from the data presented, certain general guidelines were apparent. First, repeated studies show that growth, development, and micronutrient intakes are not compromised in children consuming 27–30% of their dietary energy as fat, even during the weaning period (4–14). However, although adults appear to maintain fat balance when consuming diets that provide as little as 10% of energy as fat, dietary fat intakes of 17–22% energy have been associated with growth faltering in children. For this reason, and consistent with recommendations from the American Academy of Pediatrics Committee on Nutrition (19) and the International Dietary Energy Consultancy Group (20, 21), dietary fat intakes above a minimum of 23–25% of dietary energy should be maintained and it appears prudent to set a safety margin slightly above this range. It is important to emphasize that these considerations apply only when total dietary energy intake is from all macronutrient sources and when the intakes of other essential nutrients are each sufficient for adequate growth and development. Beyond growth and development, percentage energy from fat has been associated with the prevalence of hypercholesterolemia and obesity. As discussed in the symposium, lipoprotein responses to dietary fat intake in childhood are affected by many welldescribed single gene defects and molecular polymorphisms in lipoprotein, lipoprotein receptor, and lipid processing enzyme genes. However, to a large extent, the mechanisms underlying the altered responses are not understood and individual clinical