Had the first day of my boot camp. They devoted 10 minutes of this to a pitch for us to buy a protein shake diet called I think Isometrix, but I could be wrong about the name. My 25 second search on Google brought up non-protein-shake results. The gist of the pitch is that it is detoxifying. "Toxins build up in the body and you have to purge them!"
About half the class signed up for it. At a cost of something like $399 for a 60 day supply. Mind you, this doesn't replace your entire diet. Just part of it. If I am going to overpay to ingest something, I want it to be lattes. Others might prefer something alcoholic.