The paper “Prospective Randomized Trial of Low Saturated Fat, Low Cholesterol Diet During the First Three Years of Life” (Circulation [1996]: 1386–1393) describes an experiment in which “1062 infants were randomized to either the intervention or control group at 7 months of age. The families of the 540 intervention group children were counseled to reduce the child’s intake of saturated fat and cholesterol but to ensure adequate energy intake. The control children consumed an unrestricted diet.”

a. The researchers concluded that the blood cholesterol level was lower for children in the intervention group. Is it reasonable to conclude that the parental counseling and subsequent reduction in dietary fat and cholesterol are the cause of the reduction in blood cholesterol level? Explain why or why not.

b. Is it reasonable to generalize the results of this experiment to all children? Explain.