Milk fat and gastrointestinal illness.

The population of a pediatric practice was followed prospectively and determinants of acute gastrointestinal illness were evaluated in a nested age-matched case-control study. Children over age one taking low fat milk as their only milk source in the three weeks prior to illness had five times the risk of a doctor's visit for acute gastrointestinal illness as did children taking only whole milk during the same time period. This increased risk could not be explained by numerous potentially confounding variables or potential biases. There was no indication that the increased risk differed for rotavirus positive or rotavirus negative illness, or that it varied by children's age.