Of course, there are the most widely known Islamic rules that alcohol, pork and the by-product of pork are Haram, but Halal culture extends beyond that, and it is even more than about diet. Halal literally means anything that is permissible or lawful to a Muslim, so Halal is a lifestyle and not just a diet-plan.
To zero down on the Halal diet, though, it is important to note that Halal requires food to be wholesome and clean. Here are the restrictions (the no-no’s) involved in a Muslim’s diet under the Islamic law:
Animals that were slaughtered in the name of anyone else apart from Allah (God). Animals that were slaughtered incorrectly or that were dead before the slaughtering. Carnivores. Birds of prey. Some reptiles and birds that do no have external ears. Blood and foods contaminated by blood (and alcohol, and all of the mentioned above.)
If it gets a little too difficult, though (for example, if you can’t find a Halal restaurant where you are), it’s useful to note that all seafood is Halal.