It aint that simple man. Nothing is black and white, it's all shades of grey. When the body is functioning properly, you will unconsciously adjust meal frequency and volume. Your body will even up-regulate your metabolism to burn off excess energy. However, when you are addicted to carbs and sugar, satiety hormones become overrun. I suggest you research leptin resistance. Repeated overeating will lead to fat accumulation, but overeating isn't actually that easy when you are eating primally. Food simply loses its' appeal after a certain point.
I am not just pulling this out of my ass to make excuses for myself. I never was fat. I just recognize that this is a multi-faceted issue, and poorly represented by the formula of calories in=calories out.