> Like you, I don't imagine I could gain weight eating raw chicken

I also find that idea hard to imagine for myself.

Perhaps this has already been discussed here, but one theory to explain carb
cravings is that carbohydrate, by stimulating the release of insulin, clears
the way for an increased uptake of the amino acid tryptophan by the brain.
Tryptophan acts as a precurser in the brain to the neurotransmitter
serotonin, which in most people curbs appetite. Serotonin is the
neurotransmitter whose uptake is inhibited by Selective Serotonin Reuptake
Inhibitors (SSRI's) like Prozac. The "fen" in the now defunct but hugely
popular diet medication Phen-Fen was Fenfluoramine, another SSRI.

If one's brain has grown dependant on large increases of serotonin to curb
appetite, as could happen on a high-carb diet, then it stands to reason that
one's brain might come to crave carbs when one's new low-carb diet no longer
caused excessive spikes in insulin. One non-pharmaceutical solution then
might be to increase one's intake of dietary tryptophan to compensate.

It may be no coincidence, Todd, that you and I and others cannot imagine
ourselves over-eating a meal of unspiced chicken. Chicken meat is a rich
source of tryptophan.

-gts