I think maybe he goes overboard and overcomplicate some things, almost as if there is a 'magic bullet'. At least he correct on the big issue: it's not one thing. There are usaully more than one factor for any given activity or skill, including bodybuilding. With the training stimulus, you can turn potential strength in to actual strength, so real effort is beneficial. And to support additional weight some calories must be ingested—slightly more—like Adonis says. Rest, as well because "muscles grow not in the gym".
