Think you’re eating healthy? Guess again. Chances are you’re not doing as well at mealtime as you think.

That’s what a federal study suggests. Researchers have previously established that self-reported health is generally a good predictor of well-being and mortality later in life. U.S. Department of Agriculture scientists wanted to know if people are as accurate reporting their diets as their health.

Investigators pulled data from the National Health and Nutrition Survey, which every two years quizzes Americans about the things they eat. The survey asked about 9,700 people to rate their diet as either excellent, very good, good, fair or poor. Later, participants were asked to recall what they had eaten to see how accurately they were reporting their meals.

For purposes of rating the responses, the best diets were those containing fruits, vegetables, seafood, whole grains, low-fat dairy products and plant proteins. Sorry, people — donuts were not on the list.

Groceries on the naughty list included refined grains, edibles high in salt or saturated fats and anything with sugars. Potato chips pitched their tent here.

The study shows that an astonishing 85% of those who took part in the study had the wrong perception of just how healthy they were eating.

This doesn’t necessarily imply deception, as when a guy whose fridge is filled with pizza and beer tells a new, health-conscious girlfriend that he loves broccoli.

Sometimes, we just don’t understand the true health value of everything we eat.

But some of us do: The study showed that nearly everyone who reported having an awful diet was spot-on. They’re aware of their own foibles, and aren’t worried about what others think.