If you’re looking to tone up and shred some belly fat, you've got to do more than simply hit the gym. “Abs are made in the kitchen,” is the common refrain from trainers and nutritionists alike because your diet is a far more effective way to lose the layer of midsection fat that's obscuring your six pack. And cutting out carbohydrates should be the cornerstone of your nutrition plan when you're looking to lean up. A Harvard study of more than 60,000 dieters found those who cut back on bread, pasta and starches lost more weight than those who simply cut back on fat and calories. But not all carbs are created equal. The truth is, there are some good, healthy carbohydrates that can serve you well, especially when you're cutting out the junk like white flour and refined sugar in order to lose the spare tire.