5 simple tips to help you cut calories and stay satisfied.

If you're tired of hearing diet advice to eat less, we have news you're going to love."By picking foods that are naturally lower in calories but larger in volume, you can eat a lot more food without worrying about what it will do to your waistline," says Barbara Rolls, Ph.D., author of The Ultimate Volumetrics Diet (William Morrow, 2012). In fact, we tend to choose our food based on volume-not calorie count-and the quantity of food we eat each day stays remarkably consistent even though the number of calories we wolf down can vary. So, "lowering your food's calorie density," as researchers call it, is a smart-and healthy-way to satisfy your appetite and cut calories. These five research tested tips let you put this concept into practice.

-Karen Ansel, M.S., R.D.

Tip #1. Add Liquids

Broth or water instantly adds bulk to your meal for almost no calories. Think about it: 1/2 cup of black beans has about 115 calories, yet, for the same 115 calories you could slurp an entire cup of black bean soup. Women who ate low-cal soup twice daily for a year lost 50 percent more weight than women who ate the same number of calories in the form of two energy-dense snacks, according to an Obesity Research study.

Tip #2. Jam It with Veggies

Vegetables are loaded with fiber, which automatically lowers the calorie density of your food because your body can't digest it entirely. When South Korean researchers fed women an equal volume of either plain rice or rice with added vegetables, those who feasted on the veggie-filled rice downed 41 percent fewer calories and felt more satisfied afterwards.

Tip #3. Pump It Up with Air

Incorporating air into foods puffs them up. "Because airy foods are bigger, they trick your brain into thinking you're eating more," says Barbara Rolls. The proof: researchers at Penn State University gave volunteers a similar-size snack of dense Cheetos Crunchy or more voluminous Cheetos Puffs. Those who munched on the puffs ate 70 fewer calories even though they polished off 73 percent more by volume. When possible, opt for airy eats: Cheerios over granola, bread over crackers and tubular pasta like rigatoni in place of spaghetti.

Tip #4. Serve Up Salad

Simply adding a serving of salad to your meal can help you eat 11 percent fewer calories, according to a 2012 Appetite study. Stick with voluminous, low-calorie fixings like fresh veggies and leafy greens and limit add-ons like nuts, seeds and cheese. If you'll be making your salad into a main meal, add lean protein, such as skinless chicken, grilled shrimp or salmon, tofu or beans, to help you feel satisfied longer.

Tip #5. Trim the Fat

"With twice as many calories per bite as carbs or protein, fat calories add up incredibly quickly," says Rolls. So the more fat on your plate, the less food you can eat without racking up the calories. Keep fat in check by choosing lower-fat options of your favorite foods, such as lean cuts of beef, skinless poultry and nonfat dairy, and trim any visible fat off meat before cooking.