It is not what you are putting in your body that is making you fat. It is, instead, how much you are putting in your body that is causing your weight to increase. I frequently tell patients that they can gain weight on an all vegetable diet and that they can lose weight on an all candy diet.  A calorie is a calorie.  In regard to weight loss, the body does not care about the source of the calories.  A calorie, by definition, is the amount of energy contained in a food. If you consume more energy than you are expending, your body will then take the excess energy and store it (as fat) for the future. The only difference between a dieting strategy of eating all vegetables or all candy is simply a matter of malnutrition (not to mention that you probably will not feel very good eating only candy).

Your body has a certain amount of calories that it burns every day  for basic needs.  For women, this is approximately 1800 calories per day.  For men, this figure is about 2200 calories per day.  If you consume fewer calories than these in any given day, your body will have to break down stored energy (fat) for fuel.  When trying to lose weight, you should not feel as though you cannot consume your favorite foods.  You simply need to make sure that you consume your desired foods in moderate quantities keeping in mind their caloric value. I can guarantee you that if you eat no more than 1200 calories per day, you will loose weight.