what vegans don't seem to understand or accept is that the use of fire to cook raw meat in the past greatly increased the protein content which in turn helped development both physically and more importantly mentally. this is a key reason why modern humans evolved beyond their ancient contemporaries. without the proper level of protein Newton's strength and recovery are greatly affected. if the dude is gonna go vegan fine but he could keep his protein levels up in any number of other ways, like protein shakes.
i myself like a good steak .. medium well and a scotch to wash it down with!