Marah
If you're tklniag strictly about weight gain, and no other health issues with regard to fat or no fat, the calories are what the calories are.However, I've seen articles in the past that claimed that your body uses more calories to process the carb calories than it does to process the fat calories. In other words if you eat an equal amount of carbs than fat in one meal for example, a bigger part of the fat calories will be stored as fat than do the carb calories.