“We found that only a small percentage of U.S. adults can accurately assess the healthfulness of their diet, and interestingly, it’s mostly those who perceive their diet as poor who are able to accurately assess their diet,” said researcher Jessica Thomson. “Additionally, most adults overrate the quality of their diet, sometimes to a substantial degree.”
Who’s eating healthy?
The researchers analyzed responses from nearly 10,000 adults enrolled in the National Health and Nutrition Examination Survey. Participants completed questionnaires about what they ate and drank in the last 24-hour period and then ranked how healthy they believed their diets to be. The researchers gave participants four categories to describe their diets: poor, fair, good, very good, or excellent.
The researchers then used the questionnaires to come up with an overall rating of the participants' actual diets. Ultimately, about 85% of the participants inaccurately assessed their own diets, and 99% of those people scored their diets healthier than they actually were.
Among participants who rated their diets as fair, good, very good or excellent, they only matched the researchers’ rankings between 1% and 18% of the time. However, those who determined their diets to be poor had much better success, matching the team’s ranking 97% of the time.
Moving forward, the researchers hope that more work is done to get a better baseline understanding of consumers’ thought processes when choosing and ranking certain foods.
“It’s difficult for us to say whether U.S. adults lack an accurate understanding of the components of a healthful versus unhealthful diet or whether adults perceive the healthfulness of their diet as they wish it to be – that is, higher in quality than it actually is,” Thomson said. “Until we have a better understanding of what individuals consider when assessing the healthfulness of their diet, it will be difficult to determine what knowledge and skills are necessary to improve self-assessment or perception of one’s diet quality.”