You're working toward a healthier life, you're exercising and watching what you eat. But you may be unknowingly derailing your diet by turning to so-called "healthy" foods. These are foods loaded with hidden fat, calories, even sodium.

Bran muffins

Kimra Hawk, a Registered Dietitian at Providence St. Vincent Medical Center in Portland, identifies five "health food" offenders. She points to bran muffins, granola, tuna salad sandwiches, protein bars and frozen entrees.

Bran muffins: We eat them for breakfast for the fiber. Hawk says, in reality, "they (makers) can put just a small amount of bran in there, and call it a bran muffin, so it's really not healthy!"

Each contains as much as 23 grams of fat and 500 calories. "They're really cupcakes in disguise," she says, and you're better off eating a bagel with a glass of milk and fruit.

Granola: It's another "healthy" breakfast food many of us choose. "It sounds very healthy, but granola has oils added to it," Hawk said.

Some brands of granola have as much as 9 grams of fat in just a half-cup serving, and most of us eat significantly more than a half-cup of cereal.

Tuna Salad Sandwich: "It's a great source of healthy protein and omega three fats that we all need," Hawk said.

But, with all the added mayonnaise, the average Tuna Salad Sandwich from a Deli holds 40 grams of fat. "You're looking at almost a whole day's worth of fat in that sandwich," she warned. So go for a turkey sandwich with mustard, instead.

Protein/Energy bars: We reach for them in the afternoon when we're really craving a candy bar. "Many of them can be close to 300 calories, that's no longer a snack, that's a meal," Hawk said. So look for bars with 100 to 140 calories that also include some protein.

Frozen Dinner Entrees: Hawk loves the portions and says they're perfect for people who tend to over eat. But she's not crazy about the amount of sodium. Some have nearly a day's allowance of sodium in one serving.

"If you have high blood pressure, heart disease, other types of health issues you really do have to watch your sodium and probably stay away from these," she warned. The good news, she said, is that you can find lower sodium options but make sure the meal has less than 20 percent of your daily allowance of sodium.

The bottom line on these so-called "healthy" foods is to always read the label.

Hawk said tuna, bran, and whole-grains are all good for you. But, "if there are lots of other things added, it's not going to be healthy."

She advised to eat whole foods as much as possible. Also skip added sauces and dressings when possible. This will help you cut added sugar, fat and calories and move closer to your goal of leading a healthier life.