Hello
The BBC Click technology TV program for 27/01/2018 looked at living longer and cryogenics.
If you can’t watch the show on BBC iPlayer then this link has a summary:
http://www.bbc.co.uk/news/technology-42832015

Part of the reporting was talking about a company called HVMN that makes a ketone drink – they stated on camera that after imbibing the drink, within half an hour, the equivalent of fasting for 5 days would be produced and they took “evidence” with ketone readings.
I am pretty sure that the drink was simply being very quickly metabolised and that ketones from the drink were being released – can’t see how the drink could be breaking down fat stores to release ketones that way.
Extremely disappointed to see the BBC being persuaded to misreport in such a way, as there are some many easily influenced faddy people who will probably buy the drink – for the wrong reasons – as it does look like a good way to get an energy boost whilst exercising, which could be used to exercise longer and that could help with extra strength and increased BMR.
Of course I could be completely wrong and this drink could be a magic elixir 🙂