I don't think there are any universal answers; no right/wrong delineations.
I conk out if I don't have meat daily (ideally 3 times.) Others tell me this can't be true and, as a nutrition bore, I'm aware they are right in theory. But my experience of my body is second to none, and this is true for me. It's also true for other members of my family, and for some fellow CFS/ME sufferers.
I stopped following low-fat advice when I noticed my skin was looking a bit papery & dry. I know people who've been low-fat all their adult life, and have lovely skin. It's an individual thing.
I can handle enormous quantities of alcohol. I get drunk slowly, never "lose control" and it doesn't make me fat. I had a liver & kidney scan recently - all fine. Irritating news to others, I realise, but I take no credit for it - I was made this way. I'm not unique in this, by any means.
I gain muscle very quickly with exercise. Again, this irritates those whose muscles require more effort to tone up, but they may be comforted that I also run quickly to fat, while they stay fit for longer. Also, I can't develop speed no matter how hard I train.
The extract OP linked intrigued me, as the protein/exercise thing seems to fit me exactly! Wonder if the same team looked at alcohol metabolism in people with that gene?