Valter Longo is the guy who designed (and, yes, profits from) these diet kits. He’s a biogerontologist and cell biologist, seems quite well respected, invited onto reputable podcasts, and has solid credentials from what I can tell. He definitely has his reputation riding on this product, and even if we think of it very cynically and just assume, for sake of argument, that he’s just trying to make money, ruining his reputation on a bogus product would not be a great long-term investment for somebody who wants to live past 100. The idea of the diet is that it has just about 700 calories a day, spread thin over the length of the day with small mini meals given at specific times, very little solid foods since it’s largely soup based, and the idea is that the nature and the quality of the food will be perceived by the body as eating practically nothing and that therefore the body will nonetheless go into a fasted state, or close to it, reaping the benefits such as autophagy over a period of 5 days. I have done the diet myself, a few times, and each time I lost several pounds, which is nice even if it’s not entirely the point, and I felt very good afterwards. Whether autophagy cleared out my misfolded proteins and paved the way towards sweet sweet longevity, it’s hard to say. I do like that the product tells me exactly what to do and exactly what to consume and when, so there are absolutely no choices to make. I like the completeness and simplicity of it.