I would not call them allergies, but rather current food sensitivities. I developed a lot when I ate a plant-based diet. In the end I could only eat white fish, chicken and i think 5 types of vegetables. Everything else caused big issues. I healed a lot of these sensitivities with a cooked carnivore diet plus a lot of raw dairy. A carnivore diet is the ultimate elimination diet. This should heal your vili and leaky gut, which you will likely have due to your previous veganism. If you don´t eat meat for a long time, ur body is not used to it, doesnt have the bacteria to digest it and you stomach acid will likely be very low. It´s always better to eat a raw carnivore diet rather than cooked, im sure that you can speed up your healing, but cooked worked for me too. After 6 month into carnivore I made big improvements when it comes to digesting meats (red meat was impossible for me to digest before). I also had issues with eggs, now not anymore. Pasteurized dairy I would not recommend.
Now I feel that I want to give other foods another try, so I decided to slowly transition to keto, to see if I can tolerate other foods again, and I started with fats like avocado, olive oil, coconut oil and macadamia and pecan nuts. Generally I would suggest that you eat a lot of fats, more than protein, maybe 70:30 ratio, because the meat protein could be an issue, since you increase something that ur body is not used to. I also found that my pancreas were deficient due to the previous lower fat plant-based diet. Stomach acid is only one key, bile is another important factor to break down fats. So you could be taking HCI tablets without any results, because your pancreas are not working properly. That´s at least what I think happened to me, as HCI tablets proved to be useless. Whenever I overeat protein I feel my pancreas are overworked, so I suggest to take it easy on protein. Your body might be different, just giving my point of view. Some people here question raw dairy, but for me raw cow dairy helped a lot. Especially fermented one. Raw kefir can sometimes help too. High Meat as Dingeman suggested would be a good option too, but looking back raw dairy helped me more than high meat. But u´ll see. But I think the key is to go carnivore, with absolutely no plant foods, even herbs. You could try keto instead if u can tolerate, but carnivore in my opinion is king, high fat is essential and low carb vital to lower inflammation.
