I'm just sort of stunned that a professor thinks he can "prove" it's a matter of calories by this experiment. The logic of proof doesn't work that way. (There's no way to prove all swans are always white, but you can disprove that thesis simply by producing just one black swan.)

We all know lots of people who lost weight after restricting calories, but as has been pointed out repeatedly, there could be a number of explanations for that beyond CICO. The proof needs to go in the other direction: If one person loses weight through an increase in calories, then we know the mechanism isn't simple CICO/ELMM. There are lots of people like that on this forum, and I'm one of them. His loss on a diet of twinkies is meaningless; it's just another white swan.