Natural foods and all-natural foods are widely used terms in food labeling and marketing with a variety of definitions, most of which are vague. The term is often assumed to imply foods that are not processed and whose ingredients are all natural products (in the chemist's sense of that term), thus conveying an appeal to nature. But the lack of standards in most jurisdictions means that the term assures nothing.

People use the term junk food to describe a food that has few of the nutrients your body needs but can easily get too much of. Junk foods are processed foods consisting of high calories, but that is considered only as a broad umbrella. These foods are prepared in a way that they look appealing and are enjoyable so you are chemically programmed to ask for more.

Organic food is food produced by methods that comply with the standards of organic farming. Organic foods typically are not processed using irradiation, industrial solvents, or synthetic food additives.

Foods labeled "organic" must consist of at least 95% organically produced ingredients and the other 5% must be approved on the National List provided by the USDA.

A genetically modified organism, or GMO, is an organism that has had its DNA altered or modified in some way through genetic engineering. Genetically modified food According to the National Library of Medicine (part of the National Center for Biotechnology Information), genetically engineered, or GM, foods are those that have had foreign genes from other plants or animals inserted into their genetic codes. This has resulted in foods that are consistently flavored, as well as resistant to disease and drought.