If you're ready to jump on the vegetarian or vegan band wagon, here's a couple of points to keep in mind, and hopefully reference to as needed.
The link below shows signs of a poor vegetarian/vegan diet. An unhealthy diet can lead to severe medical issues and ailments, ultimately causing the body to suffer and shut down. View the list of various side effects often linked to poor health choices.
http://homeguides.sfgate.com/side-effects-becoming-vegetarian-79628.html
The goal is to remain healthy - while living the vegetarian/vegan lifestyle. Here is a great list to look over. This info may assist you in maintaining a balanced diet.
http://zenhabits.net/plant-fueled/