4. They Nibble on Walnuts at Snack Time
If you want to have a slim belly that is free of flab, walnuts should be one of your snacks of choice. Walnuts contain polyunsaturated fats, which have been linked to a reduction of fat storage in your body and improves your metabolism. The nuts do contain more calories than other snacks, so be sure you eat them in moderate portions. A handful is all you need to reap the benefits.