Directed at the douche-bag who wrote that "challenge":
Man, it must suck to have an entirely 2,467 word "article" based on "38 years of research on various vegan, vegetarian, or plant-based diets" virtually disproven by a single word:
chimpanzee
That's right, our closest ancestor is an omnivore, and actually hunts and kills prey, while also eating plants. Chimps are stronger, but dumber than.. well *most* humans anyway, judging by your complete lack of reality and the fact that you tried to use Comic Sans, size -1 for your disclaimer.
Still not convinced? Then I challenge you to raise a healthy child on your vegan diet, while I raise a child on an omnivore diet. As humans are omnivores, not exclusively meat-eaters despite what your over-simplified article seems to indicate.
Now, I'm cutting away all the pseudo-science here, but when your child succumbs to malnutrition, I will have have trained a ferocious baby-seal killing machine that'll be able to eat five animals for every one you don't.