I think the ray peat diet would be something with a lot of 'ifs' in it. Hed probably say ideally specific ripe fruits, eggs, gelatin, coffee, milk with weekly liver shellfish, but he knows a lot of people either cant get those or cant afford them, which is probably why he sometimes mentions other stuff as being not as bad, or that 'they lived on such a diet and were healthy' and stuff like that, saying some people lived on a potato diet and were healthy...its hard to say for sure, I guess there is an optimal peat diet, but then cascading down from there depending on circumstance. The optimal is what will heal and youthen and keep immunity the highest, where as the other stuff like potatoes or cooked greens might allow you to live pretty long and healthy but you might age as normal people do and not quite be 100% or even know what that feels like, and heal slower. Hes probably too polite to say that or doesn't want to sound arrogant, but it seems like this is kind of how he sees it