You're kidding right? Shatner's had a beer belly for the last 40 years and Patrick Stewart has always been quite thin. It's just luck and genetics.

Shatner had the gut, but did you see him use an elevator to get on Jeff's rocket? He climbed the stairs, 7 flights, roughly 70 feet above ground, at 90+ and clinically obese. Was he gasping when he got to the top? Yes. Did he do it? Yes! Did he keep up with the kids half his age? Yes!! Did he complain? No! Did they use a (danny) crane to hoist him up there? No! Could Patrick have done that? I doubt it after watching his performance in Picard. He looked and acted feeble in that. Patrick was thin, but that doesn't mean fit. Shatner was fat, but strong.