Eat with caution. In a new report, researchers from the Environmental Working Group (EWG) examined more than 84,000 food products throughout America’s grocery stores, and found at least 27 percent contain trans fat. An additional 10 percent of foods were “likely” to contain trans fat. However, out of all the food analyzed, only two percent labeled the fact they contained trans fats.

Trans fat is a chemically manufactured form of fat, industrially processed by adding hydrogen to vegetable oil — it solidifies at room temperature. By doctors’ standards, trans fat is considered the worst type of fat to consume, not only because it raises your bad cholesterol, but also because it lowers your good cholesterol. It's ubiquitously found in food products like cakes, cookies, cinnamon rolls, crackers, frosting, coffee creamer, potato and tortilla chips, microwaveable popcorn, doughnuts, and French fries. The list goes on.

Being aware that certain foods will contain partially hydrogenated oil is one way to protect your body from unhealthy additives, but EWG said other ingredients may also be worth watching out for. Refined oils, like soybean, canola, corn, and cottonseed oils, may contain small amounts of trans fats that add up over time. Flavors and food color additives are also a “likely source” of trans fats, according to their findings.

Why do American food companies get away with slipping trans fats into food without labeling their contents? Thanks to a labeling law in the United States, if a food has less than 0.5 grams of trans fat in one serving, the nutrition facts label can read, "0 grams trans fat." But hidden trans fats can add up quickly if you consume more than one serving of, say, a bag of potato chips. The responsibility is turned over to the consumer to eat with caution.

“Serving sizes are notoriously small," said the study’s coauthor Dawn Undurraga, a registered dietitian at EWG, according to Time. “There’s a lot of kids foods here. It’s really disconcerting.”

Trans fats can also be produced naturally in animal products, like meat, milk, and cheese — they're produced in the gut of certain grazing animals. But the type of trans fat EWG is concerned with is chemically created to improve the texture, shelf life, and flavor of certain foods. According to the Food and Drug Administration (FDA), approximately half of all trans fats consumed in America are sourced from artificially processed foods. In 2013, the FDA sought to ban trans fats from all food products. That's failed to go into effect so far.

One of the biggest health concerns is what happens to the body after maintaining a steady diet of foods containing trans fats. Because of its ability to raise levels of low-density lipoprotein (LDL), or "bad" cholesterol, in the blood, trans fat consumption increases a person’s risk of developing cardiovascular disease. In turn, the American Heart Association (AHA) recommends cutting back on foods that contain trans fat. Without the label to tip you off when there are hidden trans fats in products, the AHA recommends reading the ingredients list and avoiding products that include “partially hydrogenated oils.”

Source: Undurraga D. Hidden In Plain Sight. Environmental Working Group. 2015.