here is a great point for all the sides of what to do in a dietary fashion to shed fat. you can either cut carbs or cut calories. both have you cutting carbs. which is a key point as dietary sugars (of near any type) increase blood sugar the fastest and can therefore cause the greatest insulin response.
another point is that when insulin is present the body is going to be storing body fat only, as it is a one way path. so when storing, you cannot be using bodyfat as a fuel source. so think of it this way, eat lots of carbs (50+%) and eat several small meals a day, 5-8 for example, you can see how blood sugar will constantly be raised in a quick manner therefore not allowing for much usage of body fat for fuel.
im sure some may point as some have already that some cultures eat mostly carbs but they also eat fewer meals and fewer total calories. therefore they will not be causing the insulin response that we do in america with high frequency meals and especially with highly processed carbs.
seeing as how we in america usually want the quick fix and do not want to work for it i like to default to recommendations that allow for maximal usage of body fat as fuel which requires very low carbs.