Try and separate carbs and fats wherever possible, within reason. Why? Because carbs (glucose) is your body's preferred energy source, and your body will use it whenever it's present. Your body will not make efficient (if any) use of the fat you're eating along with carbs because it doesn't need to, increasing chances of it being stored as new bodyfat. Take note of the absolute worst foods you can eat - they're all high in both carbs and fats...