The very fact that one has to go through such extraordinary measures to eat vegan and stay alive should be proof enough that it isn't how we were designed. If it were not for the unbelievable infrastructure of the modern world how would one survive a vegan lifestyle? No soy, even growing your own wheat would be so labor intensive you would be in calorie deficit growing, thrashing, milling and cooking it. Meat is calorie dense compared to many foods especially fatty meats. Meat is also nutrient dense as you get concentrated nutrients from the food the animal ate. Many vegetarians don't look well but I admit there have been some successful ovo lacto vegetarian BBs. Are there any top vegan BBrs? Legit question.
