What makes fast food so tasty? Lots of salt and fat — exactly what you need to limit if you have high blood pressure, says Jennifer Cholewka, RD, CDN, a dietitian and advanced clinical nutrition coordinator at Mount Sinai Hospital in New York City.

"If you have high blood pressure, you really should make fast food a 'sometime' food," she says.

Nearly half of all adult Americans have high blood pressure — a reading greater than 130/80 millimeters of mercury — or they take medication to control their pressure, according tothe Centers for Disease Control and Prevention (CDC). High blood pressure poses a number of health threats, including heart attack, stroke, heart failure, vision loss and kidney disease, according to the American Heart Association (AHA).

Various factors can put you at risk for high blood pressure, according to the AHA. Some you can't control, such as your family history, age, gender and race. But others, including a diet high in sodium and fat, you can.

AHA guidelines recommend most Americans consume no more than 2,300 milligrams of salt a day, which is about a teaspoon. The association further recommends no more than 1,500 milligrams a day if you have high blood pressure. The U.S. National Library of Medicine notes that those with high blood pressure could benefit by adhering to the low-salt Dietary Approaches to Stop Hypertension (DASH) diet. Goals of that diet also include limiting daily fat intake to no more than 27 percent of your calories, and of those, less than 6 percent should be from saturated fat.

Cholewka does not believe that people with high blood pressure must eliminate all fast food from their diet. But you should, at the very least, make it an occasional treat, she says. "You should keep it to once a week at most or, better yet, save your fast food dining for special occasions," she says.

And when you do indulge in fast food, make sure you count it toward your day's salt and fat content, Cholewka says. Most fast food restaurants are required to post nutritional information on the foods they serve, she says, so "if you're in doubt about what you're ordering, check the nutrition charts posted in the restaurant." Alternatively, you should be able to check the fast food restaurant's menu and nutrition facts online.

Also, Cholewka says, never add extra salt from the shaker to what you've ordered — "that goes without saying."

Another option is to choose healthier options at fast food chains that are widely available today. These include salads, veggie bowls and grilled chicken. Choose lettuce wraps rather than rolls or tortillas.

Also, watch the dressings, condiments and cheese because they can add a lot of sodium to your meal. Seemingly innocent, that ketchup you put on your fries or burger is high in sodium, says the Cleveland Clinic. Portion control is another way of having some fast food without totally destroying your high blood pressure diet, according to the Center for Young Women's Health at Boston Children's Hospital. Ask for a small or kid's size order of fries rather than a large. A Double Big Mac from McDonald's has more sodium than you should eat in a day: 2,440 milligrams, according to FastFoodNutrition.org, an independent educational website. But a Little Mac has 840 milligrams, FastFoodNutrition reports. More tips from the Center for Young Women's Health: Don't supersize your meal or fall for a value meal. You could be doubling or even tripling the amount of salt, fat and calories in one sitting. And if you want a sub sandwich, ask it to be made with lean meats, such as turkey or grilled chicken.