Here, the top 10 choices for flatter abs.

1. Almonds

These delicious and versatile nuts contain filling protein and fiber, not to mention vitamin E, a powerful antioxidant. They're also a good source of magnesium, a mineral your body must have in order to produce energy, build and maintain muscle tissue, and regulate blood sugar. "A stable blood-sugar level helps prevent cravings that can lead to overeating and weight gain," says David Katz, MD, a professor at the Yale University School of Medicine. But what makes almonds most interesting is their ability to block calories. Research indicates that the composition of their cell walls may help reduce the absorption of all of their fat, making them an extra-lean nut.
Try for: An ounce a day (about 23 almonds), with approximately 160 calories. An empty Altoids tin will hold your daily dose perfectly.

2. Eggs

You won't find a more perfect protein source. Eggs are highly respected by dietitians because of their balance of essential amino acids (protein building blocks used by your body to manufacture everything from muscle fibers to brain chemicals). We like them because they keep our hands out of the cookie jar. Researchers at the Pennington Biomedical Research Center found that when people ate eggs in the morning, they felt less hungry throughout the day than when breakfast consisted of complex carbohydrates like bagels. "The protein and fat in the egg may be contributing to the feeling of satiety," says lead researcher Nikhil V. Dhurandhar, PhD.
Try for: One egg a day, unless you have high blood cholesterol, in which case you should check with your doctor first. (One egg packs about 213 milligrams of cholesterol.)

3. Soy

Soybeans are a great source of antioxidants, fiber, and protein. Plus, they're incredibly versatile. Snack on dry-roasted soybeans, toss shelled edamame into soups, and slip a spoonful of silken tofu into your morning smoothie. Liquid soy also makes a good meal replacement: A study from the Journal of the American College of Nutrition found that overweight subjects who drank a soy milk–based meal replacement lost more weight than those who consumed a traditional dairy-based diet drink.



Try for: Twenty-five grams of whole (not isolated) soy protein daily. A half cup of steamed edamame contains about 130 calories and 11 grams of protein. Four ounces of tofu (94 calories) contain 10 grams. Choose whole soy foods over products packed with "isolated soy protein" — the latter may not provide all the benefits of whole soybeans.

4. Apples

A 2003 study in the journal Nutrition found that overweight women who consumed three apples or pears a day for three months lost more weight than their counterparts who were fed a similar diet with oat cookies instead of fruits. "A large apple has five grams of fiber, but it's also nearly 85 percent water, which helps you feel full," explains Elisa Zied, RD, author of So What Can I Eat?! (Wiley, 2006). Apples also contain quercetin, a compound shown to help fight certain cancers, reduce cholesterol damage, and promote healthy lungs.
Try for: An apple (or two) a day. A study published in the Journal of Agricultural and Food Chemistry found that the Red Delicious, Cortland, and Northern Spy varieties had the highest antioxidant activity.

5. Berries

Most are loaded with fiber, every dieter's best friend. The more fiber you eat — experts say that it's best to get between 25 and 35 grams every day — the fewer calories you absorb from all the other stuff you put in your mouth. That's because fiber traps food particles and shuttles them out of your system before they're fully digested. Berries (and other fruits) are also high in antioxidants, which not only help protect you from chronic diseases like cancer but may also help you get more results from your workouts. "Antioxidants help improve blood flow, which can help muscles contract more efficiently," says Dr. Katz.
Try for: At least half a cup daily, or about 30 calories' worth. Don't limit yourself to the usual suspects, like raspberries, blueberries, and strawberries. If you can find them, add boysenberries, gooseberries, and black currants to the mix for excitement.

6. Leafy Greens

Their cancer-preventing carotenoids won't help shrink your waistline, but their low calorie count definitely will. One cup of spinach contains only about 40 calories, while a cup of broccoli has 55 calories and satisfies 20 percent of your day's fiber requirement. Most leafy greens are also a good source of calcium, an essential ingredient for muscle contraction. In other words, they help fuel your workouts.
Try for: Three servings daily. Keep a bag of prewashed baby spinach in your fridge and toss a handful into soups, salads, pasta dishes, stir-fries, and sandwiches. When you get sick of spinach, reach for a bunch of arugula, broccoli rabe, or broccolini, a cross between broccoli and Chinese kale.

7. Yogurt

People who get their calcium from yogurt rather than from other sources may lose more weight around their midsection, according to a recent study published in the International Journal of Obesity. The probiotic bacteria in most yogurts help keep your digestive system healthy, which translates into a lower incidence of gas, bloating, and constipation, which can keep your tummy looking flat.
Try for: One to three cups a day of low-fat or fat-free yogurt. Choose unsweetened yogurt that contains live active cultures. Add a handful of fresh chopped fruit for flavor and extra fiber.