The Committee on Nutrition, American Academy of Pediatrics, understandably focuses on American ethnic groups in the section of their article1 dealing with studies on lactose intolerance. Their conclusions bear out the earlier one by Bayless et al2 that although precise data are lacking on age of onset of lactose malabsorption (LM) among children in the United States, there appear to be notable differences among American ethnic groups in that regard. Bayless et al, relying on four studies of normal, healthy children,3-6 observed that substantial percentages of blacks and Mexican Americans become lactose malabsorbers at 1 to 4 years of age, whereas those white Americans who develop LM do so at age 5 or later.