Type of Formula Influences Infant Weight Gain

PHILADELPHIAInfants fed cows milk-based formula gain weight more quickly than babies drinking other types of formula, according to a new study published in the journal Pediatrics.

Researchers from the Monell Center followed 59 2-week old infants, whose parents decided to bottle feed for seven months to determine how much of a different formula type makes in infant health.  While most infant formulas are cows milk-based, other choices include soy-based and protein hydrolysate-based formulas. Protein hydrolysate formulas contain pre-digested proteins and typically are fed to infants who cannot tolerate the intact proteins in other formulas.

Thirty-five were randomly assigned a cow's milk-based formula and 24 were assigned to a protein hydrolysate-based formula. Both formulas contained the same amount of calories; however, the hydrolysate formula contained more protein and greater amounts of free amino acids and small peptides.

Over the seven months of the study, the protein hydrolysate infants gained weight at a slower rate than infants fed cow milk formula. Linear growth, or length, did not differ between the two groups, demonstrating that the differences in growth were specifically attributable to weight.

Researchers compared the data to national norms for breast-fed infants and found the rate of weight gain of protein hydrolystate infants was comparable to the breast milk standard. Infants who were fed cow's milk formula gained weight at a greater rate than the breast milk standards. Because of the faster weight gain in cow's milk-formula fed infants, researchers feel they may be at greater risk for obesity, diabetes and other weight-related diseases later in life.

Analysis of the laboratory meal revealed the infants fed the protein hydrolysate formula consumed less formula during the meal.