Here's what to eat to do it - and feel better immediately! This comes from the fitness director of Prevention magazine, Michele Stanten. Her first tip: Forget simple carbs like white flours, bread, rice and pasta. They'll give you a fast energy boost, but you'll quickly crash. Instead, eat complex carbs like whole grains, brown rice, oatmeal, and fruits and vegetables. They're loaded with fiber and you'll feel full longer - and snack less. A recent study by Brigham Young University showed eating 20 grams of fiber a day could add up to a 10 pound weight loss in a year's time, without changing anything else! Why? Because fiber whisks fat out of your system. Fiber from whole foods works best - added fiber doesn't have the same affect. Another good tip: Every day eat at least three servings of calcium and Vitamin D - usually found in dairy products. If you do this while eating a healthy diet, you'll weigh less, gain less and lose belly fat! Why? Because when your body doesn't have enough vitamin D, it holds onto fat, and prevents your body from getting the "I'm full" signal from your hormones. You do need some fat - the right fat - one of which is Omega-3 fatty acids from nuts, avocados, chocolate and fish like salmon, herring and tuna. They make you feel less hungry - which means less munching. Monounsaturated fats are also good for weight loss. Get them from walnuts, peanuts, olive oil and sesame oil. In a study, two groups of people ate the same diet - except one group also ate walnuts - and that group lost more weight. What else is great for losing weight? Water. Studies show by drinking at least four cups a day you'll lose five pounds by the end of the year - even if you change nothing else! According to the researchers at Stanford, that amount of water increases the amount of energy or calories your body burns. Finally, drink *green tea. It has antioxidants that tackle belly fat. According to the U.S. Department of Agriculture, people who drink three cups of green tea a day will lose twice as much weight as people who don't.