Hi Lex, been reading your journal on and off, I noted you had periods when you suffered increased weight on ZC, can you let me know if this is a continuousness trend? i.e first one loses weight, then gains it on ZC? Did you manage to control its? If so, how?
Early in the process of transitioning from a high carb diet to a VLC or ZC diet your body is not very efficient at using fatty acids for fuel. Cells need high concentrations of mitochondria to use fatty acids as their primary fuel where mitochondria are not needed in as many numbers when using glucose as the primary fuel. This means that the body is throwing away much of the energy from the fat that has taken the place of the carbs in the diet - so you lose weight. This gives the appearance that you can eat as much as you want of fat and protein and still lose (or at least not gain) weight and therefore calories don't count when eating VLC or ZC.
Unfortunately this doesn't go on forever. Once the body fully adapts to using fatty acids as its primary fuel source, the dietary fat can now be used more efficiently for fuel and you'll start to gain weight again. To keep weight down you must start counting calories again. This is not difficult as fat is very satisfying so if you only eat until satisfied you'll be fine. If you insist on stuffing yourself just because you think you can, you'll gain weight.
Most people start to notice this around 1 year to 18 months after starting VLC or ZC. It is also well documented in the Atkin's diet literature. People start on Atkin's, lose weight rapidly during the first year or so, and then their weight loss slows or stops altogether, and they will gain weight again if they over eat.
There is no magic in VLC or ZC other than the fact that high levels of dietary fat will satisfy you so it is easier to eat less. I've also found that if I over eat on highly saturated fat, that some of it passes through undigested making stools pasty, and of course that is energy that never becomes available to the body.
Generally I'm satisfied on 2,000 to 2,500 Kcal/day. If I eat more than this I gain weight. Not as much or as fast as when eating a high carb diet, but I will put on weight.
Hope this answers your question.
Lex