1) DHEA is not a diabetes med. In fact it's a steroid (not really an anabolic one, though it is a precursor to anabolics) and illegal in the EU. It is a substance which is lowered in older people, so older people supplement with it. 2) Metformin is a diabetes med, and it's used by antiaging enthusiasts independently and along with growth hormone 3) Fasting creates larger growth hormone spikes, and improves sugar clea…
If a "rich old white dude" could get the health benefits of fasting for a bit of cash, a lot of them are going to pay it. Lifestyle changes are hard, while cash is 'easy' for a significant part of what I imagine to be the target market.
EDIT: Apparently I should clarify the "old white dude" part of this. The study in question consisted entirely of "9 white men between 51 and 65 years of age", and I consider it entirely possible that this particular cocktail only works for that demographic.