By Kimberly A. Daly
January 12, 2011

We don't like telling you what you have to do-you can make your own smart decisions. But we're making an exception here. Follow these 11 basic rules and you will lose weight. We promise.

To Lose Weight: Pump Up The Volume

Sure, you need to think about fat and calories when considering a meal or snack. "But a food's air and water content, or volume, is important too," says Barbara Rolls, Ph.D., a nutrition professor at Penn State and author of The Volumetrics Eating Plan. "High-volume foods can fill you up with fewer calories." For example, you might not find 100 calories of raisins (about 1⁄4 cup) as satisfying as 100 calories of grapes (about 1 cup). In one study, Rolls noticed people who ate a salad piled high with fresh produce consumed 8 percent fewer calories (but felt just as full) as those who had one loaded with higher-density (and lower-volume) toppings like cheese and dressing. For volume without the calorie hit, opt for fiber-rich fruits and veggies.

To Lose Weight: Snooze More and Lose More

Forcing yourself out of bed for an early-morning workout could be sabotaging your weight-loss efforts if you're not logging enough shut-eye. New research from the University of Chicago reveals that skimping on zzz's while you're dieting causes your body to lose more water, muscle, and other tissue-instead of fat-which slows your metabolism. "Also, lack of sleep puts your body under stress," says Susan Kleiner, Ph.D., R.D., owner of High Performance Nutrition in Mercer Island, Washington, "and when that happens, it holds onto fat." Plus, it can increase your body's production of ghrelin, an appetite-boosting hormone. To Lose Weight: Don't Drink Your Calories

The average American gets 22 percent of her daily calories (roughly 350) from drinks. The trouble: "Liquids travel too quickly through your stomach for your brain to notice the calorie consumption," says Kleiner. A study in the American Journal of Clinical Nutrition found that people who cut sugary drinks out of their diet lost one pound more after six months than those who slashed the same amount of calories from food.

And sodas aren't the only drinks to be wary of, says Bob Harper, a trainer on NBC's The Biggest Loser. "You could burn 200 calories exercising for 30 minutes and then put them right back into your body by sipping a sports drink or a sugar-filled latte."

To Lose Weight: Pair Up To Pare Down

Protein, from meats, beans, and nuts, and fiber, found in whole-wheat bread and produce, are stay-slim staples. Even better: eat them together. "Fiber absorbs water and swells up in your stomach, taking up space," says Kleiner, a SHAPE advisory board member. "And protein sends a hormone signal to your body that makes you feel satiated." A study published in the New England Journal of Medicine shows that people following a diet that combines the two are more inclined to lose or maintain weight, most likely because they don't experience blood sugar spikes that can lead to bingeing.

To Lose Weight: Veg Out Once a Week

Nutritionists like to joke that no one ever got fat eating carrots. There's some truth to that: A study in the American Journal of Clinical Nutrition reports vegetarians are 15 percent less likely to be overweight or obese than their meat-eating friends. That's because vegetarians tend to take in fewer calories and fat, and more fruits and vegetables. But you don't have to go cold-turkey on the, uh, turkey to see a benefit. Try going meatless once a week: Replace ground beef in tacos with beans, or have a hummus sandwich instead of your usual ham and Swiss.

NEW BREAKFAST IDEAS: Shake up your healthy breakfast routine To Lose Weight: Front-Load Your Calories

You've heard it a million times: Don't skip breakfast. "Eating first thing revs your calorie burn," explains Bob Harper, who created our Bikini Body Countdown workout. "If you don't eat within two hours of waking, your metabolism can slow down to conserve energy." Noshing early gives you energy and bolsters your willpower to stay on track all day. In fact, researchers from the U.S. Department of Agriculture found dieters who eat a larger morning meal are more successful at losing body fat than those who don't make breakfast a priority. "Most women should aim to get 300 to 400 calories at breakfast," says Bob Harper.

In a scramble to get out the door? Do a little prep work: On Sunday, whip up a batch of hard-boiled eggs (80 calories each), and pair one with a pack of instant oatmeal made with nonfat milk and mashed banana (about 290 calories). "The protein fends off hunger," says Bob Harper, "and the carbs energize you."

To Lose Weight: Make Friends with Fat

Fat has more than twice the calories of carbs or protein, but "your body needs fat to function," says Kleiner. "When you don't get enough in your diet, your brain sends a signal to your cells to hold onto body fat." This means you might need to actually increase your fat intake in order to slim down.

In fact, a recent study in The New England Journal of Medicine found that women who ate a moderate-fat diet (35 percent of calories) shed an average of 13 pounds more-and kept them off-than those on a lowfat plan. Fat also takes longer to digest and helps fend off hunger and binges.

Look to plant sources of fat like olive oil, nuts, and avocados, as well as fish, for healthy polyunsaturated and monounsaturated fats. Assuming you're eating 1,600 calories a day, aim to keep your daily intake of fat around 62 grams, or 560 calories.

To Lose Weight: Make Food the Main Event

"People are so unaware of what they're putting into their mouths," says Kleiner, "especially when they're eating in front of a computer or the TV." But when you don't pay attention to your food, you consume more. "Our stomachs don't recognize we're full when our minds aren't focused on the meal," says Rolls. She recommends carving out time to sit down and eat at least one "mindful" meal per day. If you have to work through lunch, take bites between emails and make a conscious effort to savor each one.

To Lose Weight: Go Ahead, Have That Cookie

A study in the journal Obesity shows that women who said they followed a rigid diet were 19 percent more likely to be overweight than those with a more flexible eating plan. "When you've got an all-or-nothing mentality, you're setting yourself up to fail," says James O. Hill, Ph.D., director of the Center for Human Nutrition at the University of Colorado, Denver. "Often, one slipup will leave you feeling defeated and cause you to give up." Instead, indulge every once in a while. Kleiner suggests giving yourself five "get out of my diet free" cards weekly. Just limit yourself to one portion each time.

To Lose Weight: Be a Food Sleuth

A package or menu may claim that a food is "reduced-calorie," but that doesn't mean it's a smart pick. "When we see these good-for-you claims-low-carb, heart-healthy, or organic, for instance-we believe we can get away with eating more," says Lisa R. Young, Ph.D., R.D., an adjunct nutrition professor at New York University. Indeed, in a Cornell University study, researchers found diners at a "healthy" restaurant underestimated their meals by nearly 200 calories. Check calorie counts! You may be surprised!

To Lose Weight: Downsize Your Dishes

Counting calories is the primary tenet of weight loss, but it goes hand-in-hand with portion control. "We tend to over-consume because we often ‘eat with our eyes'-if we can see it on our plate, our brains think we need to finish it," says Young. To keep servings in check, use a smaller plate. Researchers at Cornell University found people who ate hamburgers off saucers believed they were eating an average of 20 percent more calories than they really were, while those who ate off 12-inch plates thought they'd eaten less and weren't as satisfied. So put your main meal on a salad dish instead.