I think the problem is what your body burns, how fast it burns it and whether it stores the energy released from the burning. A calorie is a calorie but if insulin is produced and too much insulin the body stores it as fat.
There are good carbohydrate foods and bad cargo hydrate foods. Its...
Eating too much of anything will make you fat but carbs can pile on the weight if you don't use the energy and its why cutting carbs will make you lose weight quickly
http://diabeteshealth.com/read/2007/04/24/5143/why-eating-too-many-carbs-makes-you-fat/