What is the relationship between religion and food?

In the past few weeks two different incidents made me stop and pause to think how much eating or not eating meat is starting to divide our society.
A vegan lifestyle, which once was a complete rarity in our country, seems to have become popular overnight among the hip and happening crowd.
This is in stark contrast with the general public, which is still very much in love with their steak and bacon.
A good example of that contrast was shown in the way the general public as well as vegans responded to the December edition of Allerhande, a popular supermarket magazine. People who like to celebrate Christmas in a traditional way, lamented the absence of classic meat-heavy recipes, while vegans rejoiced about the multitude of creative vegan recipes.
Because the complaints as well as the compliments were so vocal and heart-felt, it struck me how much veganism or refusal of it has almost become a religion of its own.
The loud complaints were nothing compared to the antisemitic vitriol that was spewn when the popular Palestinian vlogger Nas (Daily) decided to make an episode about Tel Aviv, the vegan capital of the world.

All this made me curious about the relation between religion and food laws and more specifically islamic and jewish food laws as well as to the reasons why even non-religious people get so worked up about food guidelines they are living by.

A vegan life

Over the past decades, a vegetarian life-style has become much more common and accepted than say just 25 years ago, when it was difficult to eat a satisfying meal away from home.
With the advent of wider vegetarian options, more and more people jump straight from a non-vegetarian lifestyle into veganism.