This was the explanation for why the scotch and soda diet doesn't work:

https://www.futilitycloset.com/2008/11/16/the-mensa-diet/

(If the nutritional calories in the drink had been only the same number of thermodynamic calories, the drink would have been energetically negative for the body because of its low temperature.)

Yeah, I assume this dumbification is spearheaded by the Americans.