People grow accustomed to the level that they live at no matter what that level is. This includes things like material comforts as well as food. That's why things like saving money and dieting are so hard. Changing our lifestyle level such that we reduce our frequency of pleasurable experiences or acquisitions is difficult and we tend to unconsciously compensate if we harshly alter our habits.
If I'm used to buying a new piece of clothing every month, I may feel deprived if I don't have the money to buy one in a given month. If I decided that I needed to save money and would only buy a new item every other month, I'd feel bad about it for awhile. Chances are that I'd spend the first several months buying things other than clothes to compensate for the lack of enjoyment during the month when I'm not buying something. This is why some people who want to save money go to dollar stores or raid bargain bins after vowing not to shop so much. They're looking to restore the balance without paying as high a price.
The same type of thinking operates with weight loss as well. A lot of people feel they've "been good" with exercise or eating healthily so they have earned an indulgence or an amplified portion of a healthy food. People tend to exaggerate the value of their sacrifice and underestimate the value of their "reward" such that they sabotage their progress to a great extent.
This sort of attempt to compensate isn't something which should be seen as stupid or self-deluding. It should be seen as a response to be expected in accord with human nature. We get used to a certain balance and it's hard to simply force ourselves into a new situation. It takes time to gradually reach a point of comfort with a reduction in consumption of anything, be it food or new items that we shop for.
One of the reasons I don't count calories all of the time and that I don't rule out certain foods for good is that I'm aware of the deprivation/compensation cycle and that I want to slowly change my situation such that I don't fail or compensate to the point where my efforts are pointless. I want to slowly whittle away at portion sizes and frequency of unhealthy food consumption such that there isn't a psychological (or biological) rebellion.
One example of this is my coffee consumption. I'm not one of those people who drinks black coffee and I never will be. I always cut my coffee with full fat milk (while my husband uses cream). I started out having a pretty big mug of coffee every morning which required about a half cup of fatty milk to cut it to a strength I could enjoy and throughout several months cut down to smaller and smaller cups such that I'm using an itty bitty cup now with about half as much milk as before. Since I did this reduction slowly, I don't feel deprived despite drinking about 1/2 as much coffee as before. In fact, I feel like it's just about the right amount and that I don't need more.
Similarly, I've been slowly cutting back on carbohydrate portions with evening meals in particular. Going from one day to the next from about a cup of rice to a half cup would have felt like I was starving myself. Now, it feels just fine because I've been adjusting to smaller and smaller portions through time.
If you're going to be successful in controlling any lifestyle change whether it be portion sizes or shopping too much, the chances for success will be vastly improved if you don't try and drop your levels of consumption too rapidly and set off a deprivation/compensation response. Granted, your start toward your goal will be slower, but hopefully the new levels you adjust to will have a greater sense of permanence and pave the way for lasting change.