Clinical Investigation and Reports

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1 Clinical Investigation and Reports Prospective, Randomized, Infancy-Onset Trial of the Effects of a Low-Saturated-Fat, Low-Cholesterol Diet on Serum Lipids and Lipoproteins Before School Age The Special Turku Coronary Risk Factor Project (STRIP) Leena Rask-Nissilä, MD; Eero Jokinen, MD, PhD; Tapani Rönnemaa, MD, PhD; Jorma Viikari, MD, PhD; Anne Tammi, MD; Harri Niinikoski, MD, PhD; Ritva Seppänen, DSc; Juhani Tuominen, PhLic; Olli Simell, MD, PhD Background We showed previously that repeated dietary counseling during the first 3 years of life reduces the concentration of serum nonfasting cholesterol. We have now extended the study to children 5 years of age and analyzed fasting blood samples, enabling LDL cholesterol calculations for the first time. Methods and Results Families of 7-month-old infants (n 1062) were randomized to a control group (n 522) or an intervention group (n 540) that received individualized dietary counseling with the aims of a fat intake of 30% to 35% of daily energy, a saturated/monounsaturated/polyunsaturated fatty acid ratio of 1:1:1, and a cholesterol intake of 200 mg/d. Nutrient intakes were studied biannually, nonfasting serum lipid values were studied annually, and fasting values were studied at 5 years of age. The intervention children always had lower intakes of saturated fat and cholesterol than the control children. The intervention boys had 0.39 mmol/l (P ) lower mean serum cholesterol values than the control boys between 13 and 60 months of age, but among girls, the difference was of marginal significance (0.15 mmol/l, P 0.052). Five-year-old intervention boys had 9% lower mean serum LDL cholesterol concentrations than the control boys (P ; 95% CI, 0.39 to 0.12 mmol/l), whereas no difference was observed in girls. In both sexes, serum triglyceride concentrations were similar in the 2 groups. Conclusions The restriction of saturated fat and cholesterol intake by repeated, individualized dietary counseling since infancy resulted in lower serum total and LDL cholesterol concentrations at 5 years of age. However, the effect was significant only in boys. (Circulation. 2000;102: ) Key Words: atherosclerosis cholesterol diet pediatrics prevention Atherosclerotic lesions in the coronary arteries of young US soldiers killed in action 1,2 demonstrate the silent beginning of atherosclerosis decades before the clinical symptoms of coronary heart disease (CHD) appear. Serum cholesterol values also correlate with the extent of aortic fatty streaks in adolescents and young adults. 3 As the number of risk factors to which a person is exposed increases, the severity of the person s asymptomatic coronary and aortic atherosclerosis also increases. 4 The Pathobiological Determinants of Atherosclerosis in Youth study shows that the prevalence and the extent of fatty streaks and fibrous plaques increase rapidly with age. 5 Thus, the fact that the origin of atherosclerosis is in childhood is indisputable. The reduction in dietary saturated fat and cholesterol intake in childhood may delay the development of atherosclerosis, but fears of diet-induced growth and neurodevelopmental problems have previously foiled early interventions. 6,7 In 1990, we launched the randomized prospective Special Turku coronary Risk factor Project (STRIP) 8,9 with the aim of decreasing exposure of the intervention children to known environmental atherosclerosis risk factors. We recently demonstrated that low-saturated-fat, low-cholesterol diet considerably reduced the age-associated increase in serum cholesterol concentration that usually occurs in children during the first 3 years of life 9 and that the intervention had no negative impact on growth. 10,11 We have now extended the intervention and follow-up to 5 years of age and, for the first time, performed lipid determinations of fasting samples, enabling standardized triglyceride measurements and LDL cholesterol calculations. Received February 16, 2000; revision received May 4, 2000; accepted May 4, From the Cardiorespiratory Research Unit (L.R.-N., A.T.), Departments of Pediatrics (H.N., O.S.), Medicine (T.R., J.V.), and Biostatistics (J.T.), University of Turku, Turku, Finland; Hospital for Children and Adolescents (E.J.), Helsinki, Finland; and Research and Development Unit of Social Insurance Institution (R.S.), Turku, Finland. Correspondence to Dr Leena Rask-Nissilä, Cardiorespiratory Research Unit, University of Turku, Kiinamyllynkatu 10, FIN Turku, Finland. leena.rask-nissila@utu.fi 2000 American Heart Association, Inc. Circulation is available at

2 1478 Circulation September 26, 2000 TABLE 1. Daily Energy and Energy Nutrient Intakes of the and at Different Ages 8 mo* 13 mo 24 mo (n 80) (n 85) (n 177) (n 162) (n 170) (n 161) Energy, kcal ( 88 to 4) ( 51 to 27) ( 54 to 29) Total fat, ( 1.2 to 1.5) ( 3.6 to 1.3) ( 4.5 to 2.4) Saturated fat, ( 0.8 to 0.8) ( 4.4 to 3.2) ( 4.2 to 2.9) Monounsaturated fat, ( 0.5 to 0.7) ( 0.4 to 0.6) ( 1.1 to 0.1) Polyunsaturated fat, ( 0.3 to 0.2) (1.1 to 1.8) (0.5 to 1.1) Cholesterol, mg ( 12.7 to 3.5) ( 36.2 to 17.7) ( 39.3 to 15.2) *Formula-fed children only. t test for comparison of intakes between groups; 95% CI of the difference in the mean between the intervention and control boys. TABLE 2. Daily Energy and Energy Nutrient Intakes of the and at Different Ages 8 mo* 13 mo 24 mo (n 71) (n 71) (n 155) (n 169) (n 143) (n 164) Energy, kcal ( 60 to 18) ( 75 to 2) ( 61 to 25) Total fat, ( 1.1 to 2.1) ( 2.6 to 0.1) ( 3.8 to 1.6) Saturated fat, ( 0.5 to 1.1) ( 3.6 to 2.1) ( 3.9 to 2.7) Monounsaturated fat, ( 0.5 to 0.7) (0.3 to 1.4) ( 0.5 to 0.4) Polyunsaturated fat, ( 0.5 to 0.2) (0.8 to 1.6) (0.6 to 1.2) Cholesterol, mg ( 15.8 to 3.8) ( 23.9 to 4.2) ( 29.3 to 4.6) *Formula-fed children only. t test for comparison of intakes between groups; 95% CI of the difference in the mean between the intervention and control girls. Methods Study Design As described in detail previously, 8, seven-month-old infants, recruited at the well-baby clinics in the city of Turku, Finland, were randomized to an intervention group (n 540) or a control group (n 522). The intervention and control families met a pediatrician and a dietitian at the Cardiorespiratory Research Unit of Turku University at 1- to 3-month and 4- to 6-month intervals, respectively; after the age of 2 years, the visits in both groups occurred at 6-month intervals. Two full-time pediatricians, 2 dietitians, and a registered nurse took part in the counseling. The parents and personnel of the daycare centers recorded the child s food consumption in a 3-day food record at 8, 13, and 18 months of age,and in a 4-day food record twice a year thereafter, always including at least 1 weekend day. The records were analyzed with the Micro-Nutrica computer program 12 with use of the Food and Nutrient Data Base of the Social Insurance Institution, Turku, Finland. 13 Nonfasting blood samples for serum lipid measurements were drawn yearly. At 5 years of age, the samples were drawn after an overnight fast. The study was approved by the Joint Commission on Ethics of the Turku University and the Turku University Central Hospital. Informed consent was obtained from all parents. Counseling The details of the dietary counseling have been described previously. 8,9 Briefly, the aims of the counseling were a fat intake of 30% to 35% of daily energy (E%), a saturated/monounsaturated/polyunsaturated fatty acid ratio of 1:1:1, and a cholesterol intake of 200 mg/d. The families were advised to continue breastfeeding or to use formula until the age of 12 months and skim milk 0.5 to 0.6 L/d thereafter. The parents were taught to add 2 to 3 teaspoonfuls of soft margarine or vegetable oil, mainly low erucic acid rapeseed oil, to the food of the 12- to 24-month-old children to maintain fat intake at 30% to 35 E%. The control families received the routine health education given to all Finnish families at the well-baby clinics. The mothers were advised to continue breastfeeding or to use formula until the child was 12 months, but cow s milk containing at least 1.9% fat (1.5% fat after May 1995) was recommended thereafter. In both groups, at least partial breastfeeding continued for 5 4 months (mean SD). All children had been weaned by 13 months of age. Because an accurate measurement of breast-milk consumption was impossible, the intake analysis at 8 months consisted only of data on the formula-fed infants. Serum Lipids Serum cholesterol, HDL cholesterol, apoa-i, apob, and serum triglyceride levels were determined as described previously. 9,14 LDL cholesterol values were calculated with the Friedewald formula. 15 All analyses were performed in the laboratory of the Research and Development Unit of the Social Insurance Institution in Turku, Finland, which regularly cross-checked lipid determinations with the World Health Organization reference laboratory in Prague, Czech Republic. Statistical Analysis The results are shown as mean SD with 95% CI for the mean values. Two-sample t test was used in comparisons of the intake data,

3 Rask-Nissilä et al Low-Saturated-Fat Diet and Serum Lipids in Children 1479 TABLE 1. Continued 36 mo 48 mo 60 mo (n 159) (n 157) (n 153) (n 149) (n 139) (n 141) ( to 0.4) ( 102 to 2) ( 81 to 33) ( 3.1 to 1.1) ( 3.1 to 0.9) ( 3.8 to 1.7) ( 3.2 to 2.1) ( 3.2 to 2.0) ( 3.2 to 2.1) ( 0.7 to 0.2) ( 0.6 to 0.3) ( 0.90 to 0.01) (0.5 to 1.1) (0.5 to 1.0) (0.1 to 0.6) ( 44.4 to 17.1) ( 45.3 to 14.7) ( 40.6 to 8.9) TABLE 2. Continued 36 mo 48 mo 60 mo (n 141) (n 149) (n 132) (n 145) (n 126) (n 133) ( 75 to 21) ( 100 to 8) ( 120 to 7) ( 3.7 to 1.4) ( 3.6 to 1.5) ( 3.5 to 1.3) ( 3.3 to 2.0) ( 3.3 to 2.0) ( 3.3 to 2.0) ( 0.9 to 0.1) ( 0.8 to 0.1) ( 0.7 to 0.2) (0.3 to 0.9) (0.2 to 0.8) (0.2 to 0.7) ( 33.8 to 5.6) ( 38.9 to 13.6) ( 40.4 to 7.8) serum LDL cholesterol and triglyceride concentrations, and growth data for the 2 groups. Because of the skewed distribution of serum triglyceride concentrations, the values were log-transformed for the statistical analysis, and CIs are not presented. Longitudinal data on serum lipid concentrations, which were normally distributed, were analyzed with the random coefficients regression model with the 7-month lipid value as covariate. This method allows an evaluation of linear trends in serum lipid values between the ages of 13 and 60 months in the series and an analysis of differences between the regression lines of the intervention and control children. 16 The differences were considered significant at P The SAS release 6.12 program package (SAS Institute) was used. At the age of 5 years, 764 children continued in the study. Children whose baseline blood sample and at least 1 later lipid measurement were successfully obtained were included in the longitudinal lipid analyses, and all available data points were used. Thus, serum cholesterol, HDL cholesterol, and non-hdl cholesterol analyses included 683 children, evenly distributed between the intervention (n 339, 181 boys) and control (n 344, 158 boys) children. The apoa-i and apob analyses included 608 children. The LDL cholesterol and triglyceride analyses included 549 children (277 intervention children [150 boys] and 272 control children [145 boys]) in whom both nonfasting baseline and fasting 5-year blood samples were available; these 549 children were thus also included in the longitudinal analyses. The representativeness of the initial study cohort of these 5-year-olds is good, because baseline weights, heights, and serum cholesterol concentrations of the infants of the initial cohort and those of the 5-year-cohort were very similar. Results Dietary Intake At the age of 8 months, the intervention children and the control children had similar intakes of energy and energy nutrients (Tables 1 and 2). The intake values for the 2 sexes were similar. After the onset of counseling, the absolute and relative intakes of fat, saturated fatty acids, and cholesterol were constantly lower in the intervention children than in the control children. Serum Lipids Because of the interaction between sex and treatment group in serum cholesterol (P 0.013) and non-hdl cholesterol (P 0.013), the 2 sexes were analyzed separately. Values for the The mean serum cholesterol values of the intervention boys were 6% to 10% lower than those of the control boys throughout the intervention (Figure 1). The random coefficients regression analysis showed a slight difference in the linear trends of the serum cholesterol values of the intervention boys and the control boys (P 0.055), indicating a tendency toward dilution of the intervention effect over time (Table 3). Similarly, the mean serum non-hdl cholesterol concentrations were 6% to 11% lower for the intervention boys than for the control boys throughout the trial. The

4 1480 Circulation September 26, 2000 Figure 1. Serum cholesterol, non-hdl cholesterol, and HDL cholesterol concentrations; HDL cholesterol to total cholesterol ratios; and apoa-i and apob values for the intervention and control boys. E, boys; f, control boys. TABLE 3. Serum Lipid, Lipoprotein, and Apolipoprotein Concentrations in the and n* 7mo 13mo 24mo 36mo 48mo 60mo 7 60mo Overall Effect (95% CI), mmol/l P Cholesterol, mmol/l boys ( 0.52 to 0.26) boys P Non-HDL cholesterol, mmol/l boys ( 0.44 to 0.21) boys P HDL cholesterol, mmol/l boys ( 0.11 to 0.03) 0.27 boys P HDL cholesterol/total cholesterol boys ( to 0.012) 0.91 boys P 0.62 apoa-i, g/l boys ( 0.09 to 0.03) boys P apob, g/l boys ( 0.09 to 0.02) 0.21 boys P *Children in whom baseline and at least 1 later lipid measurement were obtained. Mean SD of individual changes between 7 and 60 mo. Random coefficients regression analysis; P (95% CI) for adjusted group means. Random coefficients regression analysis; P for equality of slopes (13 60 mo). Adjusted for baseline (7-mo value).

5 Rask-Nissilä et al Low-Saturated-Fat Diet and Serum Lipids in Children 1481 Figure 2. Serum cholesterol, non-hdl cholesterol, and HDL cholesterol concentrations; HDL cholesterol to total cholesterol ratios; and apoa-i and apob values for the intervention and control girls. E, girls; f, control girls. difference between the linear trends of the mean serum non-hdl cholesterol values of these 2 groups did not reach significance (P 0.059). The mean concentrations of serum apob for the intervention boys were 4% to 7% lower than those for the control boys. Serum HDL cholesterol and apoa-i concentrations were in general slightly lower for the intervention boys than for the control boys, but the HDL cholesterol to total cholesterol ratios were similar for the entire study period. At the age of 5 years, the mean serum LDL cholesterol concentration of the intervention boys ( mmol/l) was 9% lower than that of the control boys ( mmol/l, P ; 95% CI 0.39 to 0.12) (Figure 3), but the mean triglyceride concentrations for the intervention ( mmol/l) and control groups ( mmol/l, P 0.25) were similar. Values for the The intervention girls had slightly lower mean serum cholesterol concentrations than the control girls during the trial (Figure 2), but the difference between groups did not reach the limit of statistical significance (P 0.052). The mean serum non-hdl cholesterol and apob values for the intervention girls and the control girls also did not differ (Table 4). The mean serum HDL cholesterol and apoa-i values for the intervention girls and the control girls differed during the follow-up, but the HDL cholesterol to total cholesterol ratios of the 2 groups were similar. At the age of 5 years, the intervention girls and the control girls had similar fasting mean serum LDL cholesterol concentrations ( and mmol/l, 95% CI 0.21 to 0.11, P 0.53) (Figure 3). The mean serum triglyceride values for these 2 groups were also similar ( and mmol/l, P 0.90). Growth A detailed growth analysis for the intervention and control children did not indicate any differences in growth for the 2 groups during the first 3 years of life. 10,11 Furthermore, the mean heights, relative heights (height for age), weights, relative weights (weight for height), and body mass indexes of the 5-year-old intervention children and control children, analyzed by sex, were similar (data not shown). Discussion This randomized long-term intervention, which at 5 years still consisted of 764 of the 1062 children initially recruited to the trial at the age of 7 months, demonstrates that a low-

6 1482 Circulation September 26, 2000 TABLE 4. Serum Lipid, Lipoprotein, and Apolipoprotein Concentrations in the and n* 7mo 13mo 24mo 36mo 48mo 60mo 7 60mo Overall Effect (95% CI), mmol/l P Cholesterol, mmol/l girls ( to ) 0.19 girls P Non-HDL cholesterol, mmol/l girls ( 0.23 to 0.04) 0.49 girls P 0.18 HDL cholesterol, mmol/l girls ( 0.09 to 0.01) girls P HDL cholesterol/total cholesterol girls ( to 0.003) girls P 0.17 apoa-i, g/l girls ( 0.08 to 0.01) 0.08 girls P apob, g/l girls ( to 0.035) 0.80 girls P 0.83 *Children in whom baseline and at least 1 later lipid measurement were obtained. Mean SD of individual changes between 7 and 60 mo. Random coefficients regression analysis; P (95% CI) for adjusted group means. Random coefficients regression analysis; P for equality of slopes (13 60 mo). Adjusted for baseline (7-mo value). saturated-fat, low-cholesterol diet efficiently reduces agerelated increase in serum cholesterol concentrations during the first 5 years of life. The adoption of a healthy lifestyle in early childhood may prevent the later development of CHD. In adults, the decrease in the incidence of CHD is assumed to be greater the earlier the decrease in serum cholesterol values takes place. 17 If a permanent reduction of serum cholesterol concentration by 10% at the age of 40 years reduces CHD risk by 54%, a diet used in our study that resulted in 6% and 9% mean decreases in serum total cholesterol and LDL cholesterol concentrations, respectively, of the 5-year-old intervention boys may considerably diminish the incidence of CHD if the effect continues into the adulthood. The decreases in serum cholesterol and LDL cholesterol concentrations in our study were consistent with the findings in other dietary intervention studies in normocholesterolemic children with 3- to 5-year follow-up, 18,19 whereas studies in hypercholesterolemic children report even larger reductions However, in the Dietary Study in Children, the net effect of the intervention on serum LDL cholesterol concentration of hypercholesterolemic children was small. 23 Unfortunately, the dietary intervention in our study did not improve the HDL cholesterol to total cholesterol ratios in either the boys or the girls. Furthermore, the intervention did not have any effect on serum triglyceride values. This finding agrees with other trials of lowered serum cholesterol concentration in children 21,22 and in adults. 24 Because we previously obtained nonfasting blood samples and, consequently, presented only HDL and non-hdl cholesterol values, the effect of intervention on LDL cholesterol has remained hypothetical until the age of 5 years. Although the HDL cholesterol values of the intervention children were slightly lower than those of the control children, the main difference in total cholesterol values is due to the lower LDL cholesterol concentrations of the intervention children, indicating the expected effect of the intervention. The effect on serum cholesterol and non-hdl cholesterol levels was significant in the boys but nonsignificant in the girls, although the intervention control group differences in the composi- Figure 3. Serum LDL cholesterol concentrations of the intervention and control boys and girls at the age of 5 years.

7 Rask-Nissilä et al Low-Saturated-Fat Diet and Serum Lipids in Children 1483 tion of the diet were similar for the 2 sexes. Also, the proportion of breast-fed children and the mean duration of breastfeeding in our study were similar in the intervention and control groups, as well as in boys and girls. However, hormonal differences are clearly present in prepubertal children, and this may in part account for this finding, although there is limited research because of the insensitivity of the hormone assays. Another explanatory factor may be the sexrelated difference in the amount of adipose tissue in the body, which might contribute to the higher absolute serum lipid concentrations of the girls compared with the boys. Furthermore, it may be possible that physical activity levels of boys and girls differ. Despite repeated counseling, the trend analysis of serum lipid values of the intervention and control boys showed a slight dilution in the intervention effect over time. The true effect of the diet may in fact be stronger, as in an intention-to-treat study, even the control families are probably quite health conscious, which may cause an intervention effect in the control children. At the same time, many intervention families may not have followed the dietary advice. However, the persistence of eating behaviors appears to begin as early as the age of 2 years, 25 and food choice behaviors track in youth. 26 A fat-modified diet is often misinterpreted as a fat-reduced diet. In the present study, the primary target was to modify fat intake by reducing the amount of dietary saturated fat and replacing it with monounsaturated and polyunsaturated fats. After the age of 13 months, our secondary target was to limit fat intake to 30 E% to 35 E% until the age of 3 years and then to limit it to 30 E%. Like other recent studies in several other Western countries, the present study showed that children s relative fat intake declines rapidly after the introduction of solid foods, reaching a nadir before or around the age of 1 year. 27,28 After the age of 2 years, children s relative fat intake steadily increases, so the mean saturated fat intake of our 5-year-old control children (14.4 E%) was higher than suggested in the current Nordic Nutrition Recommendations for children 2 years of age. 29 In conclusion, a reduction in the amount of saturated fat and cholesterol in infancy and early childhood through repeated counseling reduced age-related increases in serum cholesterol and LDL cholesterol concentrations. The intervention effect was more prominent in boys. Acknowledgments This study was supported by grants from the Mannerheim League for Child Welfare, the Finnish Cardiac Research Foundation, the Foundation for Pediatric Research, Finland, the Academy of Finland, the Yrjö Jahnsson Foundation, the Sigrid Juselius Foundation, the Turku University Foundation, the Juho Vainio Foundation, the Finnish Cultural Foundation, the Varsinais-Suomi Fund of the Finnish Cultural Foundation, the City of Turku, the Raisio Group, and Van den Bergh Foods Co. References 1. Enos WF, Holmes RH. Coronary disease among United States soldiers killed in action in Korea. JAMA. 1953;152: McNamara JJ, Molot MA, Stremple JF. Coronary artery disease in combat casualties in Viet Nam. JAMA. 1971;216: Newman WP, Freedman DS, Voors AW, et al. Relation of serum lipoprotein levels and systolic blood pressure to early atherosclerosis: the Bogalusa Heart Study. N Engl J Med. 1986;314: Berenson GS, Srinivasan SR, Bao W, et al, for the Bogalusa Heart Study. Association between multiple cardiovascular risk factors and atherosclerosis in children and young adults. N Engl J Med. 1998;338: Strong JP, Malcom GT, McMahan CA, et al, for the Pathobiological Determinants of Atherosclerosis in Youth Research Group. Prevalence and extent of atherosclerosis in adolescents and young adults: implications for prevention from the Pathobiological Determinants of Atherosclerosis in Youth Study. JAMA. 1999;281: Pugliese MT, Weyman-Daum M, Moses N, et al. Parental health beliefs as a cause of nonorganic failure to thrive. Pediatrics. 1987;80: Lifshitz F, Moses N. Growth failure: a complication of dietary treatment of hypercholesterolemia. Am J Dis Child. 1989;143: Lapinleimu H, Viikari J, Routi T, et al. Prospective randomized trial in 1062 infants of diet low in saturated fat and cholesterol. Lancet. 1995; 345: Niinikoski H, Viikari J, Rönnemaa T, et al. Prospective randomized trial of low-saturated-fat, low-cholesterol diet during the first 3 years of life: the STRIP baby project. Circulation. 1996;94: Niinikoski H, Lapinleimu H, Viikari J, et al. Growth until 3 years of age in a prospective, randomized trial of a diet with reduced saturated fat and cholesterol. Pediatrics. 1997;99: Niinikoski H, Viikari J, Rönnemaa T, et al. 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: Hakala P, Marniemi J, Knuts L-R, et al. Calculated vs analysed nutrient composition of weight reduction diets. Food Chem. 1996;57: Rastas M, Seppänen R, Knuts L-R, et al, eds. Nutrient Composition of Foods. Helsinki, Finland: Publications of the Social Insurance Institution; Salo P, Viikari J, Rask-Nissilä L, et al. Effect of low-saturated fat, low-cholesterol dietary intervention on fatty acid compositions in serum lipid fractions in 5-year-old children: the STRIP project. Eur J Clin Nutr. 1999;53: Friedewald WT, Levy RI, Fredrickson DS. Estimation of the concentration of low-density lipoprotein cholesterol in plasma, without use of the preparative ultracentrifuge. Clin Chem. 1972;18: Hand DJ, Crowder MJ. Practical Longitudinal Data Analysis: Texts in Statistical Science. London, UK: Chapman & Hall; Law MR, Wald NJ, Thompson SG. By how much and how quickly does reduction in serum cholesterol concentration lower risk of ischaemic heart disease? BMJ. 1994;308: Friedman G, Goldberg SJ. An evaluation of the safety of a lowsaturated-fat low-cholesterol diet beginning in infancy. Pediatrics. 1976; 58: Walter HJ, Hofman A, Vaughan RD, et al. Modification of risk factors for coronary heart disease. N Engl J Med. 1988;318: Stein EA, Shapero J, McNerney C, et al. Changes in plasma lipid and lipoprotein fractions after alteration in dietary cholesterol, polyunsaturated, saturated, and total fat in free-living normal and hypercholesterolemic children. Am J Clin Nutr. 1982;35: Vartiainen E, Puska P, Pietinen P, et al. Effects of dietary fat modifications on serum lipids and blood pressure in children. Acta Paediatr Scand. 1986;75: Koletzko B, Kupke I, Wendel U. Treatment of hypercholesterolemia in children and adolescents. Acta Paediatr. 1992;81: DISC Collaborative Research Group. Efficacy and safety of lowering dietary intake of fat and cholesterol in children with elevated low-density lipoprotein cholesterol: the Dietary Study in Children (DISC). JAMA. 1995;273: Mensink RP, Katan MB. Effect of a diet enriched with monounsaturated or polyunsaturated fatty acids on levels of low-density and high-density lipoprotein cholesterol in healthy women and men. N Engl J Med. 1989; 321: Nicklas TA, Webber LS, Berenson GS. Studies of consistency of dietary intake during the first four years of life in a prospective analysis: Bogalusa Heart Study. J Am Coll Nutr. 1991;10: Kelder SH, Perry CL, Klepp K-I, et al. Longitudinal tracking of adolescent smoking, physical activity, and food choice behaviors. Am J Public Health. 1994;84: Kylberg E, Hofvander Y, Sjolin S. Diets of healthy Swedish children 4 24 months old, II: energy intake. Acta Paediatr Scand. 1986;75: Michaelsen KF. Nutrition and growth during infancy: the Copenhagen Cohort Study. Acta Paediatr Suppl 1997; Nordic Nutrition Recommendations (NNR). Nordic Working Group on Diet and Nutrition. Scand Jl Nutr. 1996;40: