Fat content of the diet among preschool children in southwest britain: II.Relationship with growth, blood lipids, and iron status

Objective. In most countries, it is recommended that adults restrict fat in take to 30% to 35% of energy to reduce the risk of coronary heart disease a nd certain cancers. However, the appropriate level of fat in the diet of ch ildren is hotly debated. It has been generally accepted that fat intake by children under 2 years of age should not be limited because of fears that n utrient intakes and thus growth and iron status might be compromised. Howev er, there is very little longitudinal information on the relationship betwe en fat intake and growth in representative populations of free-living child ren under 2 years old. The objective of this study was to investigate the r elationship between fat intake as a percentage of energy, and nutrient adeq uacy, growth, blood lipids, and iron status in 18- and 43-month-old childre n. Design. This study forms part of the Avon Longitudinal Study of Parents and Children (ALSPAC)-a geographically-based cohort study in southwest England . A randomly selected subsample of the ALSPAC cohort attended research clin ics approximately every 6 months from birth, at which a variety of anthropo metric and other measurements were made. Dietary intakes at 18 and 43 month s were assessed using a 3-day unweighed food record. A capillary blood samp le was taken at 18 months for measurement of hemoglobin and ferritin levels . Nonfasting venous blood samples were taken at 31 and 43 months and analyz ed for total and high-density lipoprotein cholesterol. The children were di vided into quartiles of fat intake as a percentage of energy (QFI). QFI gro ups were compared for the number of children reaching recommended nutrient intakes, and for anthropometry, measures of iron status, and blood lipid le vels. Participants. Nine hundred fifty-one children at 18 months and 805 children at 43 months. Results. The mean (standard deviation) percentages of energy from fat in ea ch quartile at 18 months were 31.2 (2.8), 36.1 (0.9), 39.1 (0.8), and 43.1 (2.2), corresponding to a fat intake in grams of 37.3 (8.1), 44.3 (8.1), 50 .4 (10.2), and 55.4 (12.7). The number of children failing to reach recomme nded intake levels for zinc and vitamin A fell with increasing fat intake, while the number of children consuming less than the recommendations for ir on and vitamin C rose at both ages. Despite this, there was no association between fat intake at 18 months and mean height or body mass index (BMI) at either 18 or 31 months. Fat intake at 43 months was also unassociated with concurrent or subsequent height or BMI. There was also no significant incr ease in the number of children falling below the tenth percentile for heigh t or BMI as QFI fell. Mean ferritin levels at 18 months fell in both sexes as QFI increased. Total cholesterol levels at 31 months were significantly associated with QFI at 18 months, and rose from 3.99 mmol/l in the lowest Q FI in boys, to 4.31 mmol/l in the highest QFI. QFI at 43 months was unassoc iated with cholesterol levels. Conclusions. These data do not suggest that fat intakes are an important de terminant of growth in these children, even before the age of 2 years, or t hat children at the bottom of the range of fat intakes are experiencing del ayed growth. On the other hand, there is also no evidence in this study tha t children on higher fat intakes are at a greater risk of becoming obese. I n contrast to a number of US studies, we have not found children on lower f at intakes to have lower iron intakes-indeed higher fat intakes were associ ated with a greater chance of consuming less than the recommended intake of iron and with lower ferritin levels. The association of higher fat intakes with higher total cholesterol levels among boys is of concern, as there is evidence that the process of atherosclerosis begins during the preschool y ears.