Hindu - no beef as a cow is sacred
Muslim - no pork as advocated in the Qua'an and meat must come from Muslim butchers
Christian - ??? I don't think there are any restrictions
Jewish - meat bought from Jewish butcher (Kosher) and meat cannot be eaten with dairy produce.
Vegetarian - no meat or meat products (e.g. gelatine)
Vegan - no animal derived ingredients including dairy products and eggs:friedegg:
Diabetic - avoid eating too much sugary food as it affects insulin levels. Eat small meals regularly. Don't eat and drink at the same time.
Coeliac - no gluten - wheat based foods or rye or barley
Rastafarian - cooked food but served as raw as possible so most are vegetarians. Definitely no shellfood or pig.
Hope that gets you started.