As a registered dietitian, I often get questions from family and friends about particular foods and if they are really “good for you.” People are always looking for healthy food options to give them that little bit of extra energy or that feeling that they’re eating well. But, don’t be lured into the health food abyss when making selections because many so-called healthy choices are not what they seem.

It may be no surprise that people are deceived by what Brian Wansink, Ph.D., executive director of the USDA Center for Health Policy and Promotion and the director of the Cornell Food and Brand Lab, calls the “health halo effect.” Words like “granola” and “salad” conjure up visions of healthy choices since we consider these foods healthy in their natural state. Even if you’re a well-informed, health-conscious consumer who has put on a few unwanted pounds over the past year, it may not be entirely your fault. The health halo may have something to do with it.

This phenomenon relates to people being more likely to order calorie-rich side dishes, larger drinks and indulging in a dessert, while underestimating the calories of the main meal because it is considered “healthy.” In fact, a 12-inch Italian sandwich from Subway has as many calories (540 calories) and more sodium (1800 mg) than a Big Mac (540 calories and 1040 mg/ sodium) from McDonald’s – and several more hundred calories if you add cheese and dressing.

Researchers have shown that customers of McDonald’s are more accurate at estimating the calories in their meal than the customers at Subway. Ironically, the health halo created by advertisements such as one depicting that a Subway sandwich has one-third the fat of a Big Mac does affect what people will choose to eat. Despite the fact that the Subway sandwich has as many calories as the Big Mac, people were more likely to add a drink and cookies to their Subway order, making it even more caloric than the meals ordered at McDonald’s.

Don’t be fooled by health halos. Read food labels and consider the portion size of how much you are eating. A few of the most common offenders are:

Energy bars

Many people consider these to be the perfect snack, especially if they’re involved in any sort of exercise. If you are exercising for over 90 minutes or so, these products may be useful. But for the average casual athlete, these products are loaded with extra calories. You might as well eat a Snickers bar, which has 280 calories, a similar calorie range to many energy bars. Consider calorie-controlled bars if you need something to tide you over until your next meal.

Granola

Granola sounds healthy, but watch out for the hidden fats, salt and sugar. Read the food label and don’t be fooled by the calorie count because the portion sizes are small, typically just ¼ to ½ cup. In many cases, the low-fat versions swap out the fat for extra sugar and may have as many calories as the regular version. Consider using granola as a topping for fruit or yogurt for portion control.

Salads

For many of the clients I work with, salads are one of the biggest challenges. I encourage people to eat more vegetables and leafy greens, but the toppings that many salads include today tip salad into the health halo category. Words like buffalo chicken strips, gorgonzola and pecans can turn a seemingly healthy entrée into a calorie- and fat-laden item closely resembling a double-cheeseburger. Consider the nutrition information before ordering and skip salads with multiple high-fat, calorie-laden toppings or ask for them on the side.

Yogurts

Yogurts are a great source of calcium and protein, but they are not all created equally. Several premium brands have a large amount of saturated fat; shop around and look for their low-fat versions. In most cases, these products are just as creamy as the full-fat version. Still other brands may contain a lot of added sugar. Again, check labels and consider mixing in your own fresh fruit to low-fat varieties to control calories instead of buying sugar-sweetened yogurt. Low-fat Greek yogurt is an excellent source of protein and a great choice.

Smoothies

As a mom of teenagers, my kids want smoothies. Teenagers consume on average 450 calories each day in beverages. Smoothies may seem like a tasty way to get your recommended fruit servings but studies show that beverage calories are less filling per calorie than food. Plus, the added sugars can make some smoothies the equivalent to drinking pie filling! An Orange Julius 16-ounce drink has 220 calories and 50 grams of sugar. You’re better off drinking a fresh-squeezed glass of orange juice that has 110 calories per 8-ounce serving. Consider smoothies made with whole-fruit, low-fat yogurt and no added sugars in addition to limiting the portion size. And limit juice to no more than one serving per day.

Making smart food choices and controlling how much you eat may be more important than what nutrients you are eating when it comes to maintaining or losing body weight. Don’t fall into the health halo trap. Aim to choose whole foods and always check the nutrition facts panel.