>It isn’t complicated but that ugly aspect of self-discipline rears its ugly head and when ignored demands its retribution.<
You are only partially correct. Sugar consumption, in some people, triggers an excess of insulin that causes the body to store the carbohydrates as fat instead of sending it to the muscles to be used for activity. This surge of too much insulin creates a physiological drive to eat. If the person cuts out sugars, white flour and other starches from the diet and limits his or her carbohydrate intake a day to under 60 grams or less, it’s possible not to overeat.
It’s not a matter of “self-discipline”, it’s a physiological process caused by a reaction to too much carbohydrate in the diet.
I know a bit about carbohydrate (CHO) metabolism. Years of excess CHO intake, whether it be from glucose, fructose, or grain, actually results in non-responsive insulin receptors. People who discipline themselves (this is self-discipline), as you suggested, by avoiding excess CHO consumption, do not have problems with glucose regulation. Most people simply consume way too many CHOs in the form of grain, sugar, fructose or whatever. If it comes in a box or a bag, don’t eat it.