@carorees and @SSure,
My guess is that the people SSure is referring to who have lost weight after longterm stints of ADF are a very unusual, self-selected group. ADF seems to be extremely hard for most people. I couldn't get through two weeks of it when I tried some years ago after reading through one of the more active ADF forums. And I am much more disciplined (ok, let's call it what it really is, obsessive) than the average dieter. So I suspect that the people who can stick with ADF for long enough to succeed at it, probably have significant metabolic and perhaps psychological differences from the rest of us that don't push them to overeat when they reach goal.
There are so many factors that haven't really been explored. For example, the little bits of research into the variations in how people's mitochondria function find that genetic differences can make two people otherwise with the same parameters respond very differently to exercise. Some will get no weight benefit at all, others will. My guess is that there is something similar to be found with fasting.
I just read a long, and quite tedious, but at the same time eye-opening book about epigentic changes, The Epigenetics Revolution by Nessa Cary. It made me realize that genetics is far, far more complex than the typical presentation would suggest, to the point where it makes your head hurt to think about it. But the finding that binding various bits to your genes before and after birth turns genes on and off, sometimes permanently and in a way that can be inherited, explained the very worrisome findings of epidemiological studies where it appears that grandparents' diets and nutrition status affect the health of grandchildren in surprising (and depressing) ways.
So not only do people start out with genes that are tilted in various directions due to selective pressures on their ancestors (often how common starvation was in their environment, which selected for fat storing genes particularly in women) but then there are epigenetic changes made to the genes that regulate the proteins that regulate metabolism caused by things like exposure to organic pollutants like pesticides, herbicides, plastics and plasticizers, which may or may not be reversible.
Fasting seems like it would have a strong impact on these epigentic changes. Maternal starvation at certain points in pregnancy imprints epigenetic changes on offspring that can be inherited. But the effect of involuntary fasting in animal studies and epidemiologically seems to tilt towards making weight gain easier not harder.
When you thrown in the "intermittant" component, it gets more complex, and as stated, no one has really looked into this beyond those first couple weeks when so many of us bail on ADf out of misery. And to take it further, intermittant fasting in mice fed every other day would be very different from IF in humans, given their much shorter lifespans and faster metabolisms.
Finally, one last factor that does NOT get enough attention is starting weight. The people who are trying to maintain those 100+ lb losses and who had the discipline to eat ADF for the long time it took to lose that weight are likely to be far more motivated and perhaps more obsessive than those who only had 20 lbs to lose, who don't feel the same, "Its now or never" feeling. Someone from Rudolph Leibel's team who did so much of the important research on major weight loss and its effect on metabolism was quoted (I think in the book, Fat:Fighting the Obesity Epidemic a good summary of research done in the 20th century) that the only people in his experience who had been able to maintain huge weight losses were those who were strongly obsessive. I detected quite a bit of that tone in the posts in the one ADF forum I occasionally read.
