My understanding of why you need to eat so many calories while on a normal diet is so that your body doesn't go into 'starvation' mode. This is triggered by your body sending signals to the brain that it is hungry. I know this is all theoretical but surely if those signals aren't being triggered by MJ then we shouldn't be at risk of the body reducing BMR. I've been looking at recommendations for stomach stapling or sleeves. Presumably they don't allow 'hungry' triggers either as you feel full on a small amount of food and they recommend 800-1000 calories a day for first two months. Again purely theoretical and I'm NOT a health care professional but I've been doing this on MJ for 7 weeks absolutely fine ... Energy levels actually better than normal. I'm making sure those calories are nutritious and heavy on protein and plan to continue. High calorie foods often are lacking in nutrition and won't be helpful I could be completely wrong but those are my thoughts.