David, i appreciate you sharing your thoughts. I think there is something to feeling better with over-eating as insulin can push tryptophan into the brain which becomes serotinin.
You also said: “When I finished my overfeeding period (at which point I was eating 5-6k calories a day), I had almost no energy for exercise, and my appetite was bigger than ever. Unfortunately, all those calories deprived me of physical energy, rather than providing it.” My question is how much sleep were you getting? Were you getting 10-12 hours of good sleep a day with a afternoon nap? I ask because many people begin over-feeding and the first thing that happens is they get tired, yet they fight through the urge and hope their normal sleep is enough to heal. Food is a precursor to sleep (even though conventional wisdom says the opposite) as they are both needed to heal the body. Also, as my bias is shifting towards sleep (not exercise) being the primary time for fat burning, I’ve begun to see the lethagy as something you should welcome (if you can sleep) and that some of the weight gain is from not being to sleep adequately after big meals. Sleep is not “rest” ; its a very active period of rebuilding. Ideally, we could overfeed and be on bed rest sleeping almost around the clock, but that is not practical for most of us so we eat 5,000 calories but use caffeine or will power to keep the adrenals pumping, stay awake, and then wonder why we are not healing. I know i’m guilty of this.
I realize that everyone has a different health history and response to overfeeding so i am not implying this is THE only solution, I’m just saying that being tired should be viewed as a benefit to overeating. I used to get mad when i would go on vacation and after a few days of rest and eating i would get tired and just want to sleep all the time. “SLEEP!! i’m on vacation. I need to be out exploring and enjoying things.” One day i realized i simply wasn’t listening to my body.