We explored the possibility that standard infant formulas designed as the sole source of nutrients for small, rapidly growing infants may not be equally suitable for older, larger, and less rapidly growing infants who obtain a portion of energy intake from beikost. Our approach was to consider the probable nutrient intakes of a 6-month-old hypothetic infant receiving 80% of energy intake from a standard formula and 20% from beikost, and nutrient intakes of a 10-month-old hypothetic infant receiving 50% of energy intake from a standard formula and 50% from beikost. The assortment of beikost items consumed by infants is moderately high in protein and low in fat. Calculated nutrient intakes of the 10-month-old hypothetic infant were compared with intakes of infants of similar age in two national surveys. We conclude that standard infant formulas designed for young infants are reasonably well suited to meeting the nutrient needs of infants during the latter half of the first year of life.