Single case design is a field of a research that can provide a great deal of value on efficacy for worth of larger trials but the way he’s approaching it, as others have said, is functionally useless. The data is likely pointless if you’ve thrown 100 confounding variables at the wall to see what sticks
That’s the thing, he might live a bit longer but at what cost? I would much rather enjoy my life than by a slave to a miserable routine dedicated to promoting longevity that will potentially buy me an extra decade. Like I can just eat a somewhat reasonable diet, exercise, sleep okay and with decent genetics based on my parents and grandparents I will probably make it to at least mid to late 80s, maybe longer if medicine advances. If I had genetics that suggested a strong likelihood that I would die in my 60s I would maybe be more interested
With this guys routine I could maybe push that to 100ish? I would certainly love to extend my life but not at the cost of it consuming my life. I assume he’s banking on getting to the theoretical max though, which is probably closer to 120ish, and that is substantial but then it’s like a few decades of extremely decreased mobility and mental acuity? Eh
And of course this all disregards the potential that you get cancer, murdered, car accident, etc.