A health food store is a type of grocery store that primarily sells health foods, organic foods, local produce, and often nutritional supplements. Health food stores typically offer a wider or more specialized selection of foods than conventional grocery stores for their customers, for example athletes and bodybuilders, people with special dietary needs, such as people who are allergic to the gluten in wheat or some other substance, or have diabetes mellitus, and for people who observe vegetarian, vegan, raw food, organic, or other alternative diets.