Two groups particularly vulnerable to poor nutrition are pregnant women, and infants and children. During pregnancy, proper nutrition is critical to the health of the mother and fetus. For the developing fetus, inadequate amounts of protein, vitamins, and minerals may compromise the growth of fetal tissue and organ development and increase the risk of preterm birth and low birthweight. After an infant is born, good nutrition is essential for growth and development, particularly during the first 3 years of life. With adequate nutritional intake at this crucial time for brain development, brain function can be adversely affected. Nutritional deficiencies also make a child more susceptible to lead toxicity and other environmental toxins, which can lead to permanent brain damage.
On the opposite end of the spectrum, obesity promotes serious public health problems in the United States, including heart disease, malignancy, hypertension, diabetes, and depression. Increasing incidence of obesity in children and adolescents, coupled with the knowledge that obesity in adolescence tracks into adulthood, indicates obesity may become an even more serious health problem. Children and adults with disabilities are a high risk for obesity, sometimes because of social and behavioral factors,-and sometimes because of genetic predisposition, for example, Prader-Willi syndrome or Down syndrome.