Comparative metabolic study of older infants fed infant formula, transition formula, or whole cow's milk

"Transition" or "follow-up" formulas are formulas distinct in composition from "starter" infant formulas and are used in feeding infants six months of age or older. We have performed metabolic balance studies in nine children between the ages of six and nine months using a randomized double blind cross- over design. Three diets were fed: a cow's milk-based "follow-up" formula (FUF), a standard cow's milk-based infant formula (IF), or whole cow's milk (WCM). Weight gain (g/day) was equivalent among the three groups. Fecal excretion of energy was higher on WCM than on the other two diets, with the only significant difference being between WCM and IF. Fecal excretion of fat was greater on WCM and FUF than IF (20.4%, 17.8%, and 8.4% respectively). Carbohydrate excretion and nitrogen retention were similar on all 3 formulas. Although always normal, serum albumin significantly decreased at the end of the FUF dietary period. Urine osmolality was abnormally high during the WCM period, but always within normal limits while on FUF or IF. Within the context of this study, the FUF had metabolic advantages when compared to WCM but not to the IF.