A set of nationwide guidelines that specify how the nutritional needs of the population will be met is _____.

A national nutrition policy is a comprehensive framework established by governments to guide the population's nutritional needs. This policy encompasses various strategies and actions aimed at improving food security, enhancing public health, and addressing issues related to nutrition and diet. It typically includes guidelines on food availability, promotion of healthy eating habits, education programs, and measures to combat nutrition-related diseases.

The other options do not provide a nationwide framework for nutritional needs. Food disappearance data refers to estimates based on food supply and consumption patterns, but it does not constitute a policy or guideline. Nutrition screening is a process for identifying individuals at nutritional risk, while nutritional assessment is more about evaluating an individual’s dietary intake and health status. Both screening and assessment focus on individual or small group levels, rather than a cohesive national strategy.