Well. if you go without eating meat, you have to know how to eat so that you are getting all your required nutrients. I have been a vegetarian for years, and it was trial and error for me at first. At first, I felt tired and exhausted all the time because I wasn't getting what I needed into my body. It helps to do your research and to plan your meals.
But yes, I do agree that not eating meat can often have a positive effect on your body and on the way that you feel.