The Center for Food Safety and Applied Nutrition (CFSAN, pronounced sif'-san) is the branch of the Food and Drug Administration (FDA) which regulates food, dietary supplements, and cosmetics.

"Food" within the context of FDA is a very broad term with some limitations. Products that contain meat are regulated by the USDA's Food Safety and Inspection Service, with the exception of seafood and some exotic meats. The regulation of eggs is similarly complicated by shared responsibilities between the two agencies.

Many other federal and state agencies have some overlapping or conflicting requirements for regulation of food products. For example, the EPA regulates levels of allowable contaminants in public drinking water, where the FDA regulates bottled water.

Regulation of food also includes food additives such as preservatives and artificial sweeteners. Controversies over preservatives were very important in the early days of the FDA, where volunteers participated in experimental meals with high doses of the chemicals to determine their toxicity. Levels of undesirable food additives, such as methyl mercury in canned tuna, are the responsibility of the FDA.

FDA maintains a list of additives that are used in food in the United States as well as a list of additives Generally Recognized as Safe (GRAS, pronounced grass). Products that contain ingredients that are not GRAS are usually dietary supplements (for example, many energy drinks contain stimulants which are not GRAS).

Food products may make health claims, such as the "Heart Healthy" labels on foods high in fiber. Each specific claim must be submitted and is based on the content of the food, it is not an approval of a specific product. Dietary supplements may make "structure or function" claims but cannot legally claim to cure or prevent disease unless they meet an approved health claim as a food product.

CFSAN is also responsible for food labeling, specifically the "Nutrition Facts" panel typically seen on packaged foods. Ingredient declarations are also required, and this is important for consumers with food allergies

Regulation of food includes evaluations of products which are used in food handling and storage, referred to as "food contact surfaces." Problems in this area include lead based glazes that are used to decorate ceramic dishes.