Trying out the Vegan lifestyle

In order to try to decrease some of my son's behaviors, we are in the process of going vegetarian and switching to vegan. I used to be a vegetarian before I got married and pregnant, but as I began the pregnancy, my OB stressed that I needed meat to sustain energy and protein. Now that I look back, I think the only thing I was doing was eating lots of starches and not enough sustainable protein. At any rate, I've been eating meat ever since and my weight has ballooned tremendously. In researching the Gluten free Casein free diet, I see that most of the vegan lifestyle is very similar. Right now I'm strictly trying this for my autistic son. I've replaced chicken nuggets with the "not meat" nuggets and replaced lunch meat with the veggie deli meats (just for lunch time at school). He already loves lots of fruits, but I am working on the hiding of the vegetables in his overall meals. He only drinks water - to reduce his sugar intake. He gets no dairy - cause dairy makes him extra hyper, and very little bread - cause he likes bread toooo much. I'd like to know if anyone has tried to switch their ASD child to vegan, and has it made a difference in their behavior and/ or well-being?