PEDIATRICS Vol. 106 No. 5 Supplement November 2000, pp. 1294

Lipids in Complementary Foods

Berthold Koletzko, MD

Professor of Paediatrics Head, Division of Metabolic Disorders and Nutrition Dr von Haunersches Kinderspital University of Munich Lindwurmstr. 4, D-80337 München, Germany E-mail: Berthold.Koletzko{at}kk-i.med.uni-muenchen.de

	INTRODUCTION

Top Introduction References

Background

A number of unresolved questions exist with regard to the optimum quality and quantity of the lipid content in the total infant diet after the first 4 to 6 months of life, and hence also in complementary foods. Lipids usually supply the major portion of energy in the diet of young children and of the energy stored in the organism.¹ Some 40% to 55% of the energy content of human milk are comprised by lipids,² whereas complementary foods tend to be rich in carbohydrates but relatively low in fat, therefore, the proportion of dietary energy provided by lipids tends to drop considerably with the introduction of complementary foods.³ Because dietary fat content and energy density are associated, concern has been raised as to whether low-fat content in the diets of infants and young children might compromise growth.⁴ Dietary lipids modulate the mouthfeel of foods and carry aromas; hence, the effects of lipids on organoleptic food qualities may contribute to the development of food choices and eating habits. It has been questioned whether there might be disadvantages of low-fat diets for infants and young children with respect to the supply of polyunsaturated fatty acids (PUFAs), lipid-soluble vitamins, and other antioxidants as well as on gastrointestinal functions.³ As well as the amount of lipids, the nature of the dietary fatty acids might modulate energy metabolism and hence infant growth and body composition.^5-7 The effects of reducing fat intake from the seventh month of life onwards have been carefully studied by Simell^8-11 and coworkers in a cohort of more than 1000 Finnish infants. Families were advised to reduce dietary saturated fat intake, based on the assumption that such an early intervention might be beneficial for risk reduction of later heart disease. At low dietary fat intakes of about 29% of energy intake, child growth up to the age of 36 months was not adversely affected in this carefully supervised group of infants and young children from an affluent society. However, it is not known whether adaptive mechanisms, such as a change in physical activity and total energy expenditure, may have been utilized to maintain normal growth. Thus, it is not known whether a similar fat intake would be safe in less affluent populations, particularly in infants stressed by high rates of infection or diarrhea.

The widely accepted assumption that a restriction of total lipid intake in young children might be beneficial for prevention of cardiovascular disease at a later age,¹² has been challenged because beneficial effects on lipoprotein metabolism are expected only from a reduction of saturated and trans-fats, but not of total lipids.^13,14 In this respect, it remains controversial whether there are sufficient benefits to justify a strict limitation of dietary cholesterol intake in infancy, or whether in fact there might also biological advantages of some dietary cholesterol intake.^15,16 Total fat intake is also associated with the intake of lipid-soluble antioxidants such as vitamin E that are considered to reduce oxidation of circulating cholesterol and low-density lipoproteins and, thereby, long-term cardiovascular risk.¹³ Epidemiologic studies in a population born in the 1920s raised the possibility that poor growth during the first year of life, which might result from diets with a very low fat and energy content, even increases the risk of cardiovascular mortality later in life.¹⁷ Moreover, the question has been raised whether the intake of lipids relative to protein during infancy might be associated with later development of obesity. Longer duration of breastfeeding, which provides a relatively high lipid/protein ratio, is associated with a lower probability of overweight and obesity at school age,¹⁸ whereas the early feeding of diets with low lipid/protein ratios has been associated with higher body mass indexes at later ages.^19-21 A particular group of dietary fatty acids, the so-called conjugated linoleic acids, have been reported to reduce body weight and fat deposition in animal models.^22,23 Whether similar effects exist in children is not known.

In addition to its implications for growth, body composition, and cardiovascular health, dietary lipid intakes for infants and young children are important for the provision of relatively large amounts of lipid-soluble vitamins and of PUFAs. Conventional concepts on adequate intakes of lipid soluble vitamins with complementary foods have recently been challenged by findings on major beneficial effects of additional vitamin A intakes on child health in less privileged populations.²⁴ However, our present knowledge is not enough to define optimal amounts and forms of lipid-soluble vitamin intakes with complementary foods.²⁵ PUFAs are indispensable components of structural lipids in the cell membranes of tissues and, thereby, modulate membrane functions such as membrane fluidity, activity of membrane-bound enzymes and receptors, metabolite exchange, and signal transduction. Moreover, the dietary PUFA supply modulates eicosanoid metabolism and immune functions.^26,27 The postnatal dietary supply of long-chain polyunsaturated fatty acids such as arachidonic and docosahexaenoic acids with breast milk or breast milk substitutes has been associated with the development of visual function and complex cognitive functions.^28-32 It is not known to which extent the supply of PUFA beyond the first months of life might affect the composition of plasma and tissue lipids, and possibly development.

Research Issues

Questions for further research with respect to the lipid supply with complementary foods include:

1. What are the optimal amounts of lipids in complementary foods to provide an adequate source of energy to meet the needs for energy expenditure, fat oxidation, and fat deposition and thereby support physiologic growth? 
2. To which extent does the quantity and quality of dietary lipid intake modulate energy metabolism and body composition on a short- and long-term basis? 
3. To which extent do dietary lipid intakes modulate gastrointestinal functions in the latter part of infancy? 
4. What is the relationship between lipids in foods, organoleptic food qualities, and the development of food choices and eating habits? 
5. Is there a significant effect of the quantity and quality of lipids provided by complementary foods, and by the overall diet in infancy, on the risk of cardiovascular disease later in life? 
6. What are the adequate intakes, and forms of supply, for essential lipid soluble vitamins, n-6 and n-3 polyunsaturated fatty acids?

	ACKNOWLEDGMENTS

This work was supported in part by Deutsche Forschungsgemeinschaft, Bonn, Germany (Ko 912/5-2) and by Bayerisches Staatsministerium für Arbeit und Sozialordnung, Familie, Frauen und Gesundheit, München, Germany

	REFERENCES

Top Introduction References

1. Koletzko B, Demmelmair H, Socha P Nutritional support of infants and children: supply and metabolism of lipids. Ballieres Clin Gastroenterol. 1998; 12:671-696 [CrossRef][Medline]
2. Rodriguez PM, Koletzko B, Kunz C, Jensen R Nutritional and biochemical properties of human milk: II. Lipids, micronutrients, and bioactive factors. Clin Perinatol. 1999; 26:335-359 [Medline]
3. Koletzko B Response to and range of acceptable fat intakes in infants and children. Eur J Clin Nutr. 1999; 53:S78-S83
4. Michaelsen KF, Jorgensen MH Dietary fat content and energy density during infancy and childhood; the effect on energy intake and growth. Eur J Clin Nutr. 1995; 49:467-483 [Medline]
5. Jones PJ, Pencharz PB, Clandinin MT Whole body oxidation of dietary fatty acids: implications for energy utilization. Am J Clin Nutr. 1985; 42:769-777 [Abstract/Free Full Text]
6. Jump DB, Thelen A, Mater M Dietary polyunsaturated fatty acids and hepatic gene expression. Lipids. 1999; 34:S209-S212
7. Auwerx J Regulation of gene expression by fatty acids and fibric acid derivatives: an integrative role for peroxisome proliferator activated receptors. The Belgian Endocrine Society Lecture, 1992. Horm Res. 1992; 38:269-277 [Medline]
8. Lagstrom H, Jokinen E, Seppanen R, Nutrient intakes by young children in a prospective randomized trial of a low-saturated fat, low-cholesterol diet. The STRIP Baby Project. Special Turku Coronary Risk Factor Intervention Project for Babies. Arch Pediatr Adolesc Med. 1997; 151:181-188 [Abstract/Free Full Text]
9. Niinikoski H, Lapinleimu H, Viikari J, Growth until 3 years of age in a prospective, randomized trial of a diet with reduced saturated fat and cholesterol. Pediatrics. 1997; 99:687-694 [Abstract/Free Full Text]
10. Niinikoski H, Viikari J, Ronnemaa T, Regulation of growth of 7- to 36-month-old children by energy and fat intake in the prospective, randomized STRIP Baby Trial. Pediatrics. 1997; 100:810-816 [Abstract/Free Full Text]
11. Niinikoski H, Viikari J, Ronnemaa T, Prospective randomized trial of low-saturated-fat, low-cholesterol diet during the first 3 years of life. The STRIP Baby Project. Circulation. 1996; 94:1386-1393 [Abstract/Free Full Text]
12. American Academy of Pediatrics, Committee on Nutrition Statement on cholesterol . Pediatrics. 1992; 90:469-473 [Abstract/Free Full Text]
13. ESPGAN Committee on Nutrition: Aggett PJ, Haschke F, Heine W, et al Committee report: childhood diet and prevention of coronary heart disease. J Pediatr Gastroenterol Nutr. 1994; 19:261-269 [Medline]
14. Canadian Paediatric Society and Health Canada Working Group. Nutrition Recommendations Update: Dietary Fat and Children. Ottawa, Canada: Health Canada; 1993
15. Wong WW, Hachey DL, Clarke LL, Zhang S Cholesterol synthesis and absorption by 2H2O and 18O-cholesterol and hypocholesterolemic effect of soy protein. J Nutr. 1995; 125:612S-618S
16. Van BJ, Vinaimont N, Vercaemst R, Rosseneu M. Serum cholesterol, cholesteryl ester, and high-density lipoprotein development in newborn infants: response to formulas supplemented with cholesterol and gamma-linolenic acid. J Pediatr. 1992;120(4, pt 2):S101-S108
17. Barker DJP. Fetal and Infant Origins of Adult Disease. London, United Kingdom: BMJ Publishing Group; 1992
18. von Kries R, Koletzko B, Sauerwald T, Breast feeding and obesity: cross sectional study. Br Med J. 1999; 319:147-150 [Abstract/Free Full Text]
19. Rolland CM, Deheeger M, Akrout M, Bellisle F Influence of macronutrients on adiposity development: a follow-up study of nutrition and growth from 10 months to 8 years of age. Int J Obes Relat Metab Disord. 1995; 19:573-578 [Medline]
20. Rolland CM, Deheeger M, Bellisle F. Nutrient balance and android body fat distribution: why not a role for protein? Am J Clin Nutr. 1996;64:663-664. Letter; comment
21. Rolland CM, Deheeger M, Bellisle F Nutrient balance and body composition. Reprod Nutr Dev. 1997; 37:727-734
22. Ostrowska E, Muralitharan M, Cross RF, Bauman DE, Dunshea FR Dietary conjugated linoleic acids increase lean tissue and decrease fat deposition in growing pigs. J Nutr. 1999; 129:2037-2042 [Abstract/Free Full Text]
23. Park Y, Albright KJ, Liu W, Storkson JM, Cook ME, Pariza MW Effect of conjugated linoleic acid on body composition in mice. Lipids. 1997; 32:853-858 [Medline]
24. Underwood BA, Arthur P The contribution of vitamin A to public health. FASEB J. 1996; 10:1040-1048 [Abstract]
25. Aggett PJ, Bresson J, Haschke F, Recommended dietary allowances (RDAs), recommended dietary intakes (RDIs), recommended nutrient intakes (RNIs), and population reference intakes (PRIs) are not "recommended intakes." J Pediatr Gastroenterol Nutr. 1997; 25:236-241 [CrossRef][Medline]
26. Logical and pathophysiological aspects and open questions. Lipids. 1999;34:199-205
27. Miles EA, Calder PC Modulation of immune function by dietary fatty acids. Proc Nutr Soc. 1998; 57:277-292 [CrossRef][Medline]
28. Jorgensen MH, Jonsbo F, Holmer G, Breast-fed (BF) term infants have a better visual acuity than formula fed (FF) infants at the age of 2 and 4 mo. FASEB J 1994; 8:460
29. Birch EE, Hoffman DR, Uauy R, Birch DG, Prestidge C. Visual acuity and the essentiality of docosahexaenoic acid and arachidonic acid in the diet of term infants. Pediatr Res.998;44:201-209
30. Koletzko B, Diener U, Fink M, et al. Nutrition of the extremely low birthweight infant. In: Ziegler E, Lucas A, Moro G, eds. Supply and Biological Effects of Long-Chain Polyunsaturated Fatty Acids (LCPUFA) in Premature Infants. Philadelphia, PA: Lippincott-Raven; 1999:33-52
31. Agostoni C, Trojan S, Bellu R, Riva E, Giovannini M Neurodevelopmental quotient of healthy term infants at 4 months and feeding practice: the role of long-chain polyunsaturated fatty acids. Pediatr Res. 1995; 38:262-266 [Medline]
32. Willatts P, Forsyth JS, DiModugno MK, Varma S, Colvin M Effect of long-chain polyunsaturated fatty acids in infant formula on problem solving at 10 months of age. Lancet. 1998; 352:688-691 [CrossRef][Medline]