Objective. To determine the effects of feeding regimens of varying fat composition on dietary intake and serum lipid and lipoprotein concentrations in older infants.
Design, setting, and participants. One hundred four healthy infants aged 4 to 6 months were enrolled from private pediatric practices or public health clinics and were randomly assigned to one of four feeding groups until 12 months of age.
Interventions. Infants received whole cow milk or a standard infant formula (48% to 49% of energy as fat from butterfat or a soy-coconut oil blend, respectively) or one of two nearly identical investigational lower fat follow-up formulas (36% kcal from a fat blend of palm olein, corn, and safflower oils) as their primary food source in addition to table foods.
Main outcome measures. Nutrient intakes during the study period were characterized qualitatively and quantitatively. Serum lipids, lipoprotein concentrations, and anthropometrics were determined at baseline and at 12 months of age (study completion).
Results. Total energy intake was equivalent among feeding groups. Infants fed cow milk had higher mean daily intakes of total fat, saturated fat, monounsaturated fat, and cholesterol. Linoleic acid intake by infants fed cow milk, including that from table foods, was insufficient to meet current recommendations. Mean serum total cholesterol was significantly higher in the infants fed cow milk at age 12 months, whereas mean low density lipoprotein and apolipoprotein B were lower in the infants fed the follow-up formulas. Infants consuming the infant formula or whole cow milk demonstrated greater increases in mean serum total cholesterol, low density lipoprotein, and apolipoprotein B by 12 months of age compared with infants ingesting follow-up formula. Ponderal, linear, and head circumference growth was equivalent among feeding groups.
Conclusions. (1) Older infants fed lower fat formula have adequate total energy intake and normal growth. (2) The fat composition of the diets fed to the infants influenced serum lipid and lipoprotein profiles. (3) The fat composition of cow milk is inferior compared with commercial formulas. (4) The optimal fat blend for older infants including the consequences of the standard practice of adding high percentage of coconut oil to infant formulas should be defined further.