How does Leann Rimes keep on truckin' all day without fueling up with fatty foods? Her secret: a low-glycemic index (or low-GI) diet, with foods that keep her feeling full for hours. The experts give props to the low-GI diet for whittling the waist by blasting ab fat. Try it out by combining lean protein (chicken, fish, low-fat yogurt) with whole grains (like oatmeal and nutty brown rice), plus lots of fruits, veggies and healthy fats to keep your blood sugar on an even keel and avoid the post-lunch crash and burn. Think of it as insurance against that impulsive afternoon snack.

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