I had the same results from both a vegan diet and a whole foods diets. Both diets largely excluded processed food (I'd eat tofu, fermented sauces in both, and

I had the same results from both a vegan diet and a whole foods diets. Both diets largely excluded processed food (I'd eat tofu, fermented sauces in both, and some high quality ham in the whole food diet). I think that the large ratio of vegetables and lack of simple sugars was the cause more so than the meat. I get a similar boost when following body-building diets, these include simple sugars around training time and highly processed whey isolate. I have always used them to drop weight too so you're running at a calorie deficit. On those diets I've felt fantastic except the day after the binge day (you need to have a surplus once every 7-10 days to avoid starving).