Significant health problems for animals (particularly companion animals) and women of reproductive age also result from being overweight or obese due to overeating. Overnutrition can result from increased intake of energy and/or protein. Extensive studies have shown that maternal overnutrition retards placental and fetal growth, and increases fetal and neonatal mortality in rats, pigs, and sheep (14). Results of recent epidemiological studies indicate that almost 65% of the adult population in the U.S. is overweight [defined as a body mass index (BMI) > 25 kg/m2], while 31% of the adult population is obese (defined as BMI > 30 kg/m2) (15). Many overweight and obese women unknowingly enter pregnancy and continue overeating during gestation (16). These women usually gain more weight during the first pregnancy and accumulate more fat during subsequent pregnancies. Maternal obesity or overnutrition before or during pregnancy may result in fetal growth restriction and increased risk of neonatal mortality and morbidity in humans (16).