For a quick, easy and filling breakfast that doesn't break healthy diet rules, Sharon Palmer, registered dietitian and founder of The Plant-Powered Dietitian, opts for Starbucks oatmeal. "It is such a great choice, compared to greasy breakfast skillets and sandwiches, since it's whole grain and it comes with berries and nuts. For lunch, she also loves the Taco Power Bowl at Taco Bell, done vegan — that is the vegetarian refried beans with rice and vegetable toppings. "I also love Chipotle's Sofritas, which is a plant-based protein option," she adds. "I like it topped on a salad with veggies and guacamole."

Image via Starbucks

Black beans are not only tasty and filling, but they're also extremely nutritious. They're a great source of plant-based protein, fiber, folate, iron and zinc, says Elizabeth Ward, registered dietitian and author of "Expect the Best: Your Guide to Healthy Eating Before, During, and After Pregnancy." She's a big fan of Panera's black bean soup, as well as some of its other healthy-but-fast menu items, including steel cut oats, which have a good amount of fiber, Greek yogurt, which has protein, calcium and fiber, and avocado, egg white and spinach on a bagel, which has protein, healthy fats and a moderate calorie count.

Image via Panera

Since there's a McDonald's close to her, Amy Gorin, registered dietitian nutritionist and owner of Amy Gorin Nutrition, will order an Egg McMuffin before she heads off on a road trip. "Since I'm a vegetarian, I get it without the Canadian bacon, swap the American cheese out for white cheddar and add tomato slices," she says. "The white cheddar has a little more filling protein than the American cheese and you get additional satiating fiber from the tomatoes."

Image via McDonald's

Lauren Harris-Pincus, registered dietitian and owner of NutritionStarringYOU.com and author of "The Protein-Packed Breakfast Club," tries to avoid anything labeled as crispy, crunchy or creamy. "Crispy and crunchy are usually deep-fried, like chicken breast or crunchy noodles on a salad," she says. "If a sandwich is labeled as crispy, you can ask for grilled chicken instead."

For this reason, she always opts for the Chicken & Quinoa Protein Bowl with Black Beans and Greens at Starbucks. "It has 420 calories, 27 grams protein, 9 grams fiber, 17 grams fat and 1030 milligrams sodium," she adds. "You can save some calories by using less dressing."

Image via Starbucks

Fried, yes, but according to Monica Auslander, registered dietitian nutritionist and founder of Essence Nutrition, Chick-fil-A isn't the worst choice of fast food restaurants. "At least their buns have some iota of wheat flour (though they're not 100 percent whole wheat), their chicken is antibiotic-free, you can order 'extra' lettuce and tomato on your sandwich and they even have grilled nuggets (not fried)!" she says. "They now even offer a 'superfood' side (kale-based) and a few salad entrees as well (though I would avoid the dressing)." Even the waffle fries aren't so bad in Auslander's opinion since they're not nearly as processed as other fast food locales. She often orders a small, has a few and tosses them away.

Image via Chick-fil-A