Islam is a way of life too, not just for worshiping, even tho it is revealed for the purpose of worshiping. It has much to say about diet.
1- There is the well known advice of not filling the stomach but in worst cases it is 1/3 for food, 1/3 for drinks and 1/3 to breath.
2- Fasting. Many studies show how good fasting is for the health. Fasting in Islam cover avoiding all consumables. That's generally speaking.
3- Forbidding consuming alcohol, which is a potential health risk by nature.
4- Hurting yourself in Islam is a general sin, including with diet; overeating.
5- Dead not slaughtered animals are generally forbidden to eat, except for some very few and in specific cases.
7- There is a verse in Quran that tells to eat and drink without exaggeration, which includes overeating
(Quran 7:31).
8- Is honey healthy, and does it have healing effects? The Quran specifically says so
(Quran 16:69). I believe people do use it with throat infections? Just the other day a non Muslim in the RF chat room advised me to have honey for my throat problem, and I do see medicines with honey used in it.
9- The Islamic slaughtering gets the blood out of the body of the animal as much as possible. I think this makes the meat healthier taste better and?
10- It is advised in Islam to break fasting specifically with dates. I believe dates have a high dietary value?
This is what I know so far. Sorry for the short list.