I guess this is part Catharsis but there is a question in here, I promise. For as long as I can remember have been the guy that did not push himself away from the dinner table until my belly felt like it was going to bust. I simply did not feel full until I was overly full and by then it was too late. There were actual instances of my brain telling me to stop eating but my belly told me to continue and the belly won every time. I imagined there was a physical trigger that told us when we were full, a set of nerves or sensors in the abdomen just outside the stomach that told you to stop eating as your stomach filled with food and pressed against them. I assumed that for whatever reason mine were further away and so I didn’t feel full as quick as others and I got fatter because of it. I know, I know, pretty dumb, huh?
I’ve been eating Paleo/Primal for about two months and staying VLC all the while. Admittedly, I have bounced back and forth tweaking my diet in a frantic attempt to find that magic combination that would shed fat quickly and ended up gaining about 12 lbs in the process. My final tweak came by way of a three days Atkins “fat fast” that ended Tuesday evening. I found the process uneventful and completely do-able, although had I been transitioning directly from a SAD diet I may have felt differently. Anyway things have changed. Could it be that I’ve reset my Leptin sensitivity? I’m hoping it’s not just wishful thinking, but I do feel different. Wednesday I had to push my lunch away after eating about 5 ounces of chicken breast and some asparagus. Thursday four eggs for breakfast held me until dinner without another thought for food. This morning I gave no thought to food until 11am and I never skip breakfast. Is it possible I’ve fixed a life of food abuse?
It is very possible that you have regained leptin sensitivity. In your first paragraph you described a scenario that is not far off from the truth. Peptide YY is a gut hormone that is released in response to mainly protein, and to a lesser extent fat. Peptide YY has an anoretic effect on people, and though you can feel your stomach about to explode, peptide YY is very low in obese people, so that is why you still have an appetite. Generally the bigger you are the less serum peptide YY you will have. I find that this hormone is far more important in curbing food intake and reducing apptite than leptin, as an increase in serum leptin after a meal occurs several hours after the meal.
In an article I wrote on leptin, I make the case the Peptide YY helps the obese regain CNS sensitivty to leptin, while fructose, aka HFCS or sucrose, destroys leptin sensitivity. So, if you have ditched the sugar, ramped up the protein intake, and if you are losing weight easily, you generally feel good, and you are not overly hungry, then you can say you have probably regained leptin sensitivity. Keep it up!
It's too early to say but it sounds like you are coming on to something. I have just started researching intermittent fasting and how it relates to leptin. You should google it if you havent already. It is fascinating stuff.
What you've done is a good standard protocol for correcting any metabolic syndrome issues. I think you're right on with the return of leptin sensitivity and the introduction of ketosis probably was the kick in the pants needed to cause a reset of several involved dependent systems. Congrats!