Not sure if my story is helpful. Many moons ago, probably in the late 1980's I answered an advert for volunteers to participate in a diet plan for 12 weeks. I signed up and promised to stick to a milkshake diet (3 milkshakes or soup a day that came out of a packet, the shakes could be turned into a mousse by mixing the contents with less water). As a group we had to visit the Leader's home every other evening after work to have our urine tested, making sure we were in ketosis and therefore not cheating.
The leader had to attend a seminar every month in Cambridge, we were led to believe it was at a university, though we had no evidence.
If you Google 'Cambridge Diet' it comes up with different shake diets, probably they are off-springs of the diet set up by 'Leaders' of the original Cambridge Diet. BTW I think I lost about 5 stones over those 12 weeks.