Experts say there are two basic categories of foods that can be considered "keeping it off superfoods" because they fill your tummy without piling on the calories: fruits and vegetables. And the nutrient that gives fruits and vegetables that 'staying power?' Fiber. So, if fruits and vegetables are the "keeping-it-off superfood groups," fiber may well be the "keeping-it-off super-nutrient." Protein is another super-nutrient. It's becoming more scientifically accepted that protein may help to curb appetite. Protein also offers staying power, and can slightly boost your metabolism in the process. But it's imperative that you choose your proteins wisely, because like all other foods, if you're eating more than your body needs, it'll show up on the scale as a gain, instead of a loss.

The following superfoods are smart, low-calorie choices that will benefit your weight loss efforts:

Green Tea - Researchers suspect that the catechins (helpful phytochemicals) in green tea may trigger weight loss by stimulating the body to burn calories and mildly decrease body fat. So indulge in either a hot cup or a nice tall iced glass of green tea.

Broth- or tomato-based soup - Soups can help reduce hunger before meals and increase your feeling of fullness. Low-calorie green salads - Having a low-calorie salad - which is not defined as one that's loaded with croutons, high fat dressings, and cheese - as a first course can help you feel full, thereby reducing how much you eat with your main course. Wisely choose your ingredients, and its high fiber content can be the key to helping you fight cravings later in the day.

Yogurt - Including dairy products as part of your healthy diet may promote your weight loss efforts. Choosing a light yogurt may help you fight off hunger pangs due to its combination of protein and carbohydrate.

Beans - A great combination of fiber and protein, beans help you feel full longer, which means they may work to curb your between-meal appetite.

Water - Water is your body's lifeblood, and you should be drinking it through your day. It's a great no-calorie beverage, and you can get it by drinking unsweetened tea, flavored unsweetened mineral water, regular water with lime or lemon, or even in your cucumber. In addition to helping flush toxins from the body, it can also help you feel full. So when those hunger pangs strike, try drinking a glass of water before grabbing that snack.

High-Fiber, Whole-Grain Cereal - Whole grains in general help boost fiber and the nutritional value of your meal. One of the easiest ways to give your daily diet a whole-grain boost is to have a bowl of higher-fiber whole-grain cereal as breakfast or a snack.