"Dessert" is used in academic circles as a noun form of "deserve" in addition to meaning a sweet ending to a meal. A lot of people who are losing weight focus on the notion of dessert, meaning they believe that they deserve a reward as a result of their efforts. It's my feeling that any notion of dessert is what got me to where I am now, at least in part.
In the past, it wasn't uncommon for me to say things to my husband to the effect of, "I deserve (whatever)." In particular, I would say this in regard to certain foods that I wanted. If I had a hard day, I'd say I "deserved" some ice cream to comfort me. If I was sick or tired, I'd say I "deserved" to eat something that would bring me comfort. When I had a cold, in particular, I'd crave potato chips because they were salty and carby. That made them both easy to taste with dulled senses and easy to digest with an upset stomach. If I worked hard, I "deserved" a pizza because I was too tired to cook.
One of the many things which I've tried to change about my approach to food and to life in general is to remove the notion of dessert (as in deserving) something in response to carrying out a particular behavior which should be done simply as a result of being a responsible adult. If I pay a bill, I don't get a reward. If I do the laundry, I don't get a reward. If I eat properly, I don't get a reward. Food-related behaviors which contribute to an overall lifestyle of moderation and healthfulness are not things which should require a reward for me. I should carry out these behaviors for the value of the natural consequences, not for some sort of "bonus".
I haven't "rewarded" myself throughout the 11 months I've been losing weight and at times, I have felt a bit at loose ends. Early on in the process of changing how I dealt with food, I often felt a profound sense that something pleasurable and useful (psychologically, as in a coping mechanism) had been stripped away and I had been left with nothing to carry me through. I'm guessing this is a classic addictive response.
At this point, the sense that something is missing has faded greatly. In fact, using food as a reward is something which I have managed to eliminate from conscious thought. I don't think of food as a reward, though I do still occasionally crave it for comfort or when I'm bored (and have to fight the impulse, though not nearly as often as I once did) and that may be unconsciously linked to the idea of food as a reward. My fear in using "rewards" for behavior which leads to weight loss is that I'd be merely substituting one reward (food) for another (shoes, clothes, make-up, concert tickets, etc.).
I think that perhaps my inability to see eating properly and exercising as simply part of an adult existence indicated that I was still stuck in some childhood stage of development in which I felt I should get a gold star of some sort for "being good". Note that I attribute this being mired in a childish stage to myself only. I can't speak for the psychological inner workings of anyone else and do not attribute the same underlying ideas to others.
For some people who are trying to change their life habits in the hopes of losing weight, if the food isn't the gold star, then something else should be. The problem I have with this in regards to me personally is that I think that there is a danger at the end of the weight loss process when there are no more structured goals and no justifications for rewards. If you (and by "you", I actually mean "me") never frame lifestyle habits that provide you with the health and physique you desire as mere obligations of living the type of life you wish to live, then you risk falling back into old habits when the rewards end.
For some people, they have found a way of rewarding themselves without looking like they are rewarding themselves. All of those people who make dieting and exercising their raison d'etre and obsessively focus on what they did and did not eat and what they did and did not do in terms of activity? They are rewarding themselves with their obsessive cataloging, counting, or ticking off mental goal sheets in regards to the number of minutes they exercise, vegetables they eat, or weights they lift. Their system of reward is more abstract, but it still ties their food and exercise habits to dessert, though in this case it is mental gold stars instead of manicures or iPods. It's like getting your kids to clean their rooms in response to praise as a reward instead of a new toy.
My goal has been to do the equivalent of getting the kid to clean the room because a nice clean room is more pleasant to spend time in. In essence, I want to do what I do because the body I end up in will be easier to live in and with. I have no way of knowing if this will be successful in the long run. It has been so far, and that's enough for now.