The National Cholesterol Education Program recommends that healthy Americans aged > 2 y reduce energy intake to maintain ideal body weight, saturated fat to 10% of energy, fat intake to 30% of energy, and cholesterol consumption to < 300 mg/d. Although these guidelines exclude pregnant or lactating women, nursing infants, and very young children, women with gestational diabetes, preeclampsia, and familial hyperlipidemias may benefit from them. In a normal pregnancy, serum cholesterol and triglycerides rise 25-40% and 200-400%, respectively. Multiparous middle-aged women may have an increased incidence of angina and cholesterol gallstones from the hypercholesterolemia of pregnancy. Few studies support the safety of maternal low-fat diets for the developing fetus or demonstrate benefits to the mother. Polyunsaturated fatty acids lower serum lipids, and n-3 fatty acids may improve some obstetric complications. Arachidonic acid (20:4) and docosahexaenoic acid (22:6) may benefit the psychomotor and visual development of children.