The nuts and beans and cereals are the Seed. Given no other food, you stand to get along on Seed alone. Your disposition may turn grouchy, however.
One of the great delights of living is Fruits, the many styles of flesh in which nature wraps the Seed. Flowers are included. Most fruit appear only briefly, annually, a gift of the seasons. Spicy, sweet, sometimes bitter. That fruit Eve enjoyed in the first story of the Bible makes so much sense on so many levels.
Vegetables are all of the other parts of the Plants. Leaf-Stem-Root. Mushrooms get to be vegetables. Sugar is a vegetable. So are aspirin and quinine, because those come from bark.
Meat is Animals. There is a big difference between the terrestrial and aquatic fleshes, but those remain subcategories of this food group.
Our own fingernails, lips and skin, licked blood and other parts of ourselves and our close friends that we swallow should probably be in their own food group. We'll keep it classic, and call it People.
Insects are Bugs. Shrimp should arguably fall into this category.
Minerals include salt, and the other kinds of dirt people eat.
Water is a food, I guess, if dirt gets to be a food.
Dairy and honey and any other animal secretions people deem to consume are the Luxury food group. The ability to catch a mother of another species and suckle from her, and gather the lactations and, mix with them, and let them get funky and oddly delicious, or freeze them, etc., is an outstanding achievement — not to mention how we have industrialized it! Truly, diabolically, luxurious.
Alcohol and Vinegar are specially processed from Seeds, Vegetables and Fruits. Fermentation is up there with lactation harvesting and the internet in terms of our specie's defining achievements. There are other processed foods outside the Luxury food group, but they mostly fall into the next category.
Chemicals are non-traditional, excessively modified foods or food-like substances.
Toxins and straight-up Poison, are the anti-food group. Since this category exists as a catch-all to make the overall list all-inclusive, then it includes everything from paint thinner to chunks of radioactive stuff to hot lava. Shards of glass are not included in this anti-food group, but rather (scrunch!) a Mineral: Man Eats Glass.