The author of the original write-up has asked me to describe Buddhist dietary practices, so here goes.
The main principle pertaining to food that the Buddha taught was: "Eat what is put into your bowl."
In traditional Buddhism (or Buddhism as practiced in the time of the Buddha), the monks would walk quietly through a town, holding their begging bowl. I said quietly, because it was a no-no for them to actually ask anyone for food. They were completely at the mercy of lay devotees to put some food into their bowls. The monks then ate whatever was given to them.
That means there were no restrictions: Not only could they eat anything, they were pretty much required to. They certainly were not vegetarian. Until today, the practitioners of Theravada Buddhism make it very clear that they are not vegetarian.
Indeed, the Buddha's own last meal was pork. He was invited to supper, along with several monks. The meal that was served was spoiled pork. Not deliberately spoiled: The host had no intention of harming the Buddha, indeed, he wanted to honor him. But, for whatever reason, there was a problem that caused the meat to be poisonous (they did not have refrigerators back then).
The Buddha knew about the problem (since he was fully awaken), so he instructed the monks not to eat the meat (only that particular meat, he did not tell them to become vegetarians). But not to offend the host, the Buddha himself ate the meat, and subsequently died of food poisoning.
As I wrote in Buddhist vegetarians, it is common among Chinese Buddhists to be vegetarian, and I described the reasons for that. Buddhists do not kill. It is OK for a Buddhist to eat the meat of an animal that is already dead. It is not OK to have an animal killed specifically to feed the Buddhist. But in China of centuries past it was customary to kill animals right before preparing the meal. Thus, when a monk was invited to a meal, to offer him meat would involve saying, "Oh, there you are, Venerable Monk, let me kill a chicken and cook it for you." That was unacceptable.
Because of that, Chinese Buddhist monks did not eat meat for generations. Eventually, vegetarianism became the regular life style for Chinese Buddhists, even if many are unaware of the historical reasons for that (or so said my Zen master, anyway).
Chinese lay Buddhists commonly believe that the Buddha himself was a vegetarian (and that he died of poisoned mushrooms), but that belief does not seem historically correct.
The Theravadins also traditionally do not eat after noon.
If there should be any dietary practices in modern Buddhism, they should be based on the first precept of Buddhism, which is do not kill. That means that a modern Buddhist with all the knowledge of modern nutritional science should eat first and foremost what is healthy.
Buddhism being the middle way, a Buddhist should not starve nor should he overeat, as neither is healthy.
As a Western Buddhist I prefer vegetarianism because Westerners tend to eat way too much meat. They also massproduce it: Animals are often raised just for the meat. Even if the animal is already dead, buying meat at a supermarket essentially asks to have the next animal killed.
But, ever since I have been diagnosed with diabetes, I eat some meat occasionally. I still prefer vegetarian diet for the above reasons, but given that meat has very few carbohydrates (which are harmful to me), I sometimes eat it. When I do, I prefer beef over poultry because at least one cow can feed many humans, while one chicken will only feed one or two. So, at least, I try to minimize the number of animals that have to die.
That also illustrates another important thing about Buddhism: Buddhism is not a set of dos and don'ts. The Buddha showed us the way and each one of us has to decide what is the proper course of action in his own situation.
While this is not strictly about diet, the Buddha also encouraged us not to take mind-altering drugs, so alcohol is generally avoided by Buddhists.
So, since the title of this node is about laws and restraints, I would essentially have to say there aren't any in Buddhism. There are practices and traditions. They differ from country to country, and from century to century. The only "rule" I can think of is the one I mentioned right at the beginning: Eat what is put into your bowl.