I'm a vegan. I abstain from eating any animal products.
Well I applaud you. I don't have the discipline for it. What types of health benefits does veganism bring?
If you eat a well planned vegan diet, it can reduce the risks of certain types of chronic disease like heart disease.
That's a good benefit, but what about with respect to the GI system? I imagine it would keep things pretty...regular, right?
I don't have any issues. Veganism is also acceptable for all stages of life including during infancy and pregnancy.
Why do you think people who are vegan are usually so insufferable about it? You obviously aren't, but I'm just asking in general.
I guess it's an ethical thing. People abstain from eating animals and it makes them feel better than other people. 
That air of superiority turns a lot of people off from veganism I think, because people start to see it as a culture rather than a set of dietary choices.
Vegetarianism
Vegetarianism is the practice of abstaining from the consumption of meat (red meat, poultry, seafood, and the flesh of any other animal), and may also include abstention from by-products of animals processed for food.
Vegetarianism may be adopted for various reasons. Many people object to eating meat out of respect for sentient life. Such ethical motivations have been codified under various religious beliefs, as well as animal rights advocacy. Other motivations for vegetarianism are health-related, political, environmental, cultural,
in all things.
- On July 20, 2017, emeritus professor in nutrition Martijn Katan from Vrije Universiteit Amsterdam called the film "propaganda", which exaggerates the health risks of meat, eggs and dairy, and rather dangerously claims veganism prevents or cures just about any disease, like cancer or diabetes. However, he stressed that everyone should eat less meat than the population currently does on average, and that going completely vegan can be a healthy lifestyle if you make sure you get all nutrients you need (though this