Meat and vegetables would make me sedentary from having inadequate glycogen for physical work and exercise.

How about: some pasta and bread to enable physical exertion.

I know a guy that has had meat only for 3 years now. Most fit guy I know.

My father and I have avoided carbs for a few years now. Can do home renovations, gardening, dirt bike riding, and hikes better than we ever did eating carbs. Unless you're doing long distance hikes/running/hard core sports, I really don't think that's true.

He’s probably thinking of ghrelin (or NPY), but leptin and insulin both act as satiety signals too, although weaker than the hunger signal.