We are vegetarian, so I don't have any experience with organics meats. That's terrible that they are spraying them with gmo during processing, how frustrating!
We have found that we thought that she was sensitive to certain foods. We thought that she couldn't have dairy because she seemed sensitive. We also thought for a while that it was the gluten. Soy seemed to cause her to react. What we have found, is that it is just the pesticides, but not the food. She is so severely sensitive to pesticides, that even if she has a small exposure, she will tic. Fruit of all kinds is a big trigger, especially apples. She also has a huge reaction to potatoes that are non-organic. This includes potato flour in bread for instance. Corn is also a huge trigger. Nuts, as well.
Now she has no food restrictions at all. She can eat anything as long as it is 100% organic. If she accidentally eats anything that is not organic, especially fruit or potatoes, she will tic until it leaves her system, about two weeks. Some foods only cause her tics for about three days. Now that we have been extremely strict about her diet for several months, she seems to be healing and her body reacts less strongly when exposed to pesticides. Last summer her tics were constant and complex. The longest time between tics was less than two seconds. It was terrible. When we were eating mostly organic, we saw very little change. It wasn't until we went 100% until we actually saw a huge difference. It took a long time to realize what things we kept accidentally eating without realizing. Once we bought organic spices, and organic vitamins, etc, we saw that the tics completely went away.
What I realize is that since certain foods are treated with more pesticides than others, we started to think that it was those particular foods that were the trigger. What we found was that it was the pesticides themselves. She eats any kind of fruits, nuts, dairy, corn, eggs, vegetables, etc without reaction.
Also, we noticed a huge difference in her impulse control with no pesticides! I hope this helps!