What is the public health impact?

Other than the NHANES, no national surveys have been able to provide estimates of usual dietary intakes or objective assessments of physical activity, sleep, and muscle strength. The NHANES estimates contribute to public health aims in several arenas:

• Surveillance. The ability to estimate the population's distribution of usual intakes of foods and nutrients, within a survey that also assesses health and other risk-related behaviors (such as physical activity), allows researchers the unique opportunity to study relationships among all these factors. The muscle strength assessment provides the first national measure of this aspect of fitness since the 1960s, and the objective measure of sleep duration has never been collected.
• Health Promotion/Disease Prevention. Several of the Healthy People 2020 objectives relate to food and nutrient intake (e.g., those on fruits, vegetables, and whole grains).
• Health Policy. The Dietary Guidelines for Americans represent a statement of federal nutrition policy, and they guide all federal nutrition education and food assistance efforts. The release of the 2008 Physical Activity Guidelines for Americans highlights the increased focus on this behavioral risk factor. Usual dietary intake estimates and objective estimates of physical activity will help in assessing how well the public is following those guidelines.
• Health Disparities. Because the NHANES sample is nationally representative and includes persons from a range of income, education, and sociocultural backgrounds, the resulting estimates of food intake and physical activity can be examined by many variables to determine whether there are differences in these behaviors that may result in health disparities.