Anybody interested the doctors from the USC article on aging above and here[1] about simulated fasting now have a startup for it http://l-nutra.com/prolon/ and here https://prolonfmd.com/ though only available in US, Italy and Australia right now. It's a 5 day fast once a month for overweight people or every couple of months for in shape people. No idea what the price is.
The price is zero, because the necessary information to do exactly the same thing yourself with plain old food is available in the papers and in the vast number of calorie/micronutrient information sites out there online, and it is really, really easy to just go and do that.
The point of Prolon is that it is a way to obtain money from the regulatory/Big Pharma system in order to do more research into quantifying the benefits fasting and calorie restriction. Not that it is anything special in and of itself. It is just food, less of it.
[1]https://news.ycombinator.com/item?id=9741137