The Whole30 diet relies on you eliminating so-called ‘bad’ or trigger foods from your diet for 30 days. The things that need to be eliminated from your diet include dairy, grains, alcohol, legumes (this includes soy of any kind which means no tofu, soy, or miso), any added sugar of any description, and any processed or junk foods. If you see carrageenan, MSG, or sulfites on the label, then your food is processed and cannot be included.
The list might appear to be quite restrictive, but there is also a lot you can still eat while on the Whole30 diet. Ingredients that are allowed on the Whole30 diet included any vegetables, fruits in moderation, unprocessed meats (be careful with things like sausages and check for added sugars or preservatives), seafood, eggs, and all nuts and seeds apart from peanuts (they are a legume), olive oil, coconut oil, ghee, and coffee (without the sweeteners or dairy).