When the urge for a snack strikes, the best strategy is simple: Help yourself. When made with well-chosen ingredients, snacks can help keep your cardiovascular system in good form and even make it easier to maintain a healthy weight.

It's worth thinking about snacks as mini meals, and not something you grab mindlessly. Rely on the following power combos -- packed with vegetables, fruits, seeds, nuts, beans, skim-milk dairy products, fish, and whole grains -- when afternoon hunger cravings strike.

Remember to keep portions small: Each snack should have 200 calories at most. That doesn't mean it can't satisfy, though. This salad fills a whole plate (and your stomach) for only 161 calories.

Avocado is rich in the healthful fats that can raise levels of HDL ("good") cholesterol. Cantaloupe and papaya are high in potassium, which helps regulate blood pressure.

Snacking has gotten a bad rap because of high-calorie, nutrient-poor junk food, says Penny Kris-Etherton, a professor of nutrition at Pennsylvania State University. "That's too bad, because smart snacking can be an important part of a healthy diet."

Nuts, for example, are loaded with heart-protective unsaturated fats. Dark chocolate can assist in lowering blood pressure, and the antioxidants in dried blueberries may stave off arterial plaque.

Having a few bites when you're hungry can also help control your appetite, so you don’t' get famished and overeat later, Kris-Etherton says. And replacing low-nutrient goodies with smarter picks will benefit your heart.

Sardines are incredibly rich in omega-3 fatty acids, which may reduce triglyceride levels.

In a recent study, researchers at the Unviersity of California-Los Angeles compared two groups: One snacked on pretzels, the other on richer-in-nutrient pistachios. After six weeks, the pistachio eaters had significantly lower levels of triglicerides, particles in the blood that are a marker of heart-disease risk.

The fiber in whole-wheat pita and dried apricots will keep you feeling full longer.

The key is to always have healthy ingreidents on hand. A few minutes of slicing and prepping in the morning will make it much easier to opt for a healthy snack once 3:00 rolls around.

Extra-creamy but with no saturated fat, nonfat Greek yogurt is a great replacement for sour cream in these salsa tacos

Snackers have a better shot at getting the full complement of recommended nutrients -- including many that may protect against heart disease, such as antioxidants and omega-3s. Apples, for example, are high in soluble fiber, which may help lower LDL ("bad") cholesterol.

Getting protein from seafood and beans, rather than meat, is a good way to keep arteries clear.

Rich in antioxidants and polyphenols, wine and chocolate (in moderation) may rein in blood pressure and lower the risk of heart disease. Pair 3/4 ounce of the bittersweet stuff with a 3-ounce glass of wine.