IS YOUR DIET HEALTHY? Are you sure? A new study suggests that Americans struggle to get the right answer.

Investigators recently sought to determine if they could use a single question as a screening tool for nutrition studies. Currently, nutrition researchers commonly use detailed dietary questionnaires.

For the National Health and Nutrition Examination Survey, subjects completed detailed 24-hour dietary recall questionnaires. These study participants then rated their diets as excellent, good, fair, or poor.

Is your diet worse than you think?

What would be your answer if I asked you this simple question: How healthy is your diet? A recent online study suggests that we may not have great personal insight.

While historical research indicates that self-rated health strongly predicts morbidity and mortality, we do not know if self-rated diet quality products the actual quality of one’s diet.

The researchers used the food recall questionnaires to score each subject’s diet quality. Foods regarded to be less healthy included those with added sugars, saturated fats, or refined grains.

On the other hand, the researchers classified healthy foods like whole grains, fruits and vegetables, healthy fats, seafood, lower-fat dairy products, and plant proteins.

Self-rating diet quality: Surprising results

There appeared to be significant discordance between the researcher-calculated scores and how the study participants rated their diet. The differences are quite large:

• Eighty-five percent of subjects inaccurately assessed their diet quality. Of these, 99 percent overrated the healthfulness of their diet.
• Those who rated their diet as poor appeared the most accurate, with the researcher’s score matching the subject’s rating 97 percent of the time. For the other four rating categories, concordance ranged from one to 18 percent.

So which do you think it is: Do American adults lack an accurate understanding of what constitutes a healthy diet? Or are we more aspirational, perceiving the healthfulness of our diet as we wish it to be?

Please note that the study will be presented later this month and has not yet been peer-reviewed.