You can’t go wrong eating “healthy” foods. Or can you?

You know you’re not doing yourself any favors when you eat junk food. But you may not realize how your healthy food choices could also sabotage your diet.

A recent study published in the Journal of the Association for Consumer Research looked at how our perceptions influence our eating habits. The researchers analyzed how three groups of participants reacted when offered food depicted as either healthy or unhealthy.

Participants were randomly assigned to receive a healthy label or an unhealthy label on their foods. In reality, all participants received the same foods.

The researchers found that when you eat food you believe to be healthy, you’re more likely to take larger portions — and eat more. That may be because you equate healthy foods with being less filling. It’s what the researchers call the “healthy = less filling intuition.”

“Be extremely careful when consuming foods with ‘healthy’ labels,” Jacob Suher, a doctoral student at the University of Texas at Austin and the study’s lead author, told Healthline.

“The research finds that people have an unconscious belief that healthy foods are less filling than unhealthy foods,” he said. “This leads people to be hungrier after eating, order greater quantities, and over consume foods when they are labeled as healthy as opposed to unhealthy.”

Suher and his colleagues say the problem could be even worse if unhealthy foods are portrayed as healthy.

In future research, they will look at whether organic foods lead to specific biases in consumption decisions. They also want to study how labels affect how much we consume when eating to feel full vs. eating for pleasure.

“The type of eating mode may determine whether a label increases or decreases consumption,” Suher said.

Read More: Why is Nutrition Advice so Confusing? »

What Does “Healthy” Mean?

Liz Weinandy, R.D. at The Ohio State University Wexner Medical Center, said Food and Drug Administration guidelines are meant to keep unhealthy products from using the word “healthy” on their labels.

“However, there are likely many unhealthy or less-than-healthy foods that qualify to put the word on their labels under the current guidelines,” she told Healthline.

Defining healthy on a food label isn’t always simple. Weinandy uses chocolate milk as an example.

“Milk has a lot of nutrients in it, including calcium, riboflavin, potassium, iodine, protein and is fortified with vitamin D. Does adding chocolate to it make it unhealthy?,” she said. “You will find arguments on either side, but what we really need to look at is the bigger picture, which is the total diet, not just whether the milk is chocolate or plain.”

Suher said portraying a food as healthy or guilt free is a common tactic for marketers wanting to increase market share. He believes the research provides an alternative route.

Another of the study’s findings was replacing the word “healthy” with the word “nutritious” might encourage people to eat less.

“Rather than portraying a relatively calorie-dense food [such as a cookie] as healthy, which can have the ironic effect of increasing portion sizes, marketers should portray their foods as ‘nourishing’ [or strengthening or wholesome],” Suher said. “As opposed to healthy, nourishing is associated with feeling full and promotes well-being. In this way, marketers can satisfy consumers without increasing the likelihood of overconsumption.”

Read More: How Food Labels Can Suck Us Into the 'Health Halo' »

Which Health Foods Pack on the Pounds?

Weinandy said the foods to watch out for are those that are high in calories despite being small in size. These would include nuts, seeds, and oils.

“It doesn’t mean we should not eat them,” she said, “but that we should watch the amounts.”

Mindy Haar, Ph.D., of the New York Institute of Technology’s School of Health Professions, is a registered nutritionist and fellow of the Academy of Nutrition and Dietetics. She advises consumers to check labels for portion size.

“Even the calories from unprocessed healthy foods such as nuts, raisins and other dried fruits, and whole grain cereals, add up when what we think of as one portion size is really more like three or four,” she said.

Haar told Healthline that manufacturers are quick to pick up on food trends. They know once something has a “healthy” connotation, consumers may not examine the food label.

She points to a gluten-free diet, which is primarily used to treat Celiac disease. Right now, products with a “gluten-free” label have a healthy reputation. Haar cautions these foods are sometimes loaded with sugar and other starches. They may be highly processed and low in fat and fiber, so they can leave you unsatisfied.

“Gluten free certainly does not mean fat-free or low-fat, so some products may be high in the fat category as well,” she said.

According to Haar, high protein shakes and bars are often "souped up" candy bars and beverages that may be full of sugar, fat, and calories.

Chips made from vegetables instead of potatoes are another example.

“They may have a tad fewer calories than the traditional product but are certainly not low calorie,” Haar said, “especially when more than one serving is eaten at a time.”

Read More: A Gluten-free Diet May Not Do You Any Good, Experts Say »

Tips to Avoid Accidental Overeating

“Many people will eat something just because it tastes good and is available,” Weinandy said. “Coupling eating with other activities can be especially dangerous. Think eating and watching TV or eating and surfing the computer… it is totally mindless and so easy to do.”

Drink water or a low-calorie beverage when you feel hungry, she advises. Then wait five minutes to see if the hunger passes.

She also suggests using smaller bowls and plates because the bigger the portion, the more we tend to eat.

Another of Weinandy’s tips is to never eat out of a bag. Instead, take a handful or a serving of the food. Put it in a plate or bowl to enjoy. Wait five minutes before going back to get more.

“Most of us have no idea how much food we’re eating,” said Weinandy. “Food labels show what a standard serving is usually. It is very helpful to have an idea of what a serving size looks like. Knowledge is key here.”

Read More: Cancer Survivors Aren't Eating As Well As They Should »