have come to agree with your conclusion that sugar - particularly, in my own case and in the experience of several of my clients - does often increase one's desire for more sugar. In fact, for me, that is its greatest danger. A small amount of sugar seems to do the general population little harm, and as someone with a long-term "sweet tooth", I find it sometimes more productive to have a small dessert than to feel deprived and unsatisfied. The trouble is, very few people seem to be able to consume a small amount of sugar.
I have also come to the conclusion that the "danger time" for sugar consumption seems to be late in the afternoon, when many people want (some would say need) a "pick me up", and when it is a sugary one, they then crave more sugar, so the two biscuits with a cup of tea becomes 4 biscuits, and the tea often has added sugar etc etc. Sometimes the craving remains, and people find they keep picking and snacking while they make dinner.
What I advise people, and I have tried this myself with good results, is to try to replace the afternoon snack with lower GI carbohydrate and protein. 9 Grain Vita Weets with a cube of cheese; yogurt with berries etc (yes, it has sugar, but it seems more satisfying than the biscuits that seem to be in every office, every kitchen, every school and most hospital staff rooms!) To advise people, as some diet books do, to quell their hunger with carrots and celery just seems to be unsatisfying - I certainly find it so.
Having decided that although I was not overweight at 60.5 kg and 166 cm, that I would like to lose a couple of kilos while I train for a marathon, I have found this technique to help, and am now almost my ideal of 58-59 kg with no feelings of hunger or deprivation, and good energy levels except on those days of very early starts, when I am sometimes lucky enough to be able to have a "power nap". I also find, and advise others, that what I have for lunch also affects how I feel mid-afternoon; individuals vary with what works best to keep them feeling alert, but obviuosly, higher GI foods are more likely to lead to a slump.
Having said all that, i still do enjoy the occasional sugar treat, but I try to keep it small and consume it in the evening. I eat a dessert once or twice a week but if I am really feeling the urge for something sweet, I happily consume one chocolate (ferrero rochers are a favourite) or one to two small biscuits. FOr some reason, by evening, I have no trouble limiting the amount; having one does not lead to a craving for more.