Prior studies have shown that self-rated health strongly predicts morbidity and mortality, but there is little research on whether self-rated quality of diet is accurately predictive of the actual quality of one's diet.
The researchers involved in the current study used food recall questionnaires to score each participant's diet quality. Wanting to replace or enhance the detailed dietary questionnaires commonly used in nutrition, the researchers aimed to see whether or not a single, simple, question could be used as a screening tool for nutrition studies.
Using data collected from the National Health and Nutrition Examination Survey, a nationally representative survey of U.S. adults conducted every two years, the researchers asked the participants to complete a detailed 24-hour dietary recall questionnaire and rate their diet as excellent, very good, good, fair, or poor.
The study revealed that there was a substantial disconnect between the researcher-calculated scores and how participants ranked their diet. Roughly 85% of the more than 9,700 participants inaccurately assessed the quality of their diets. Of those, nearly 99% overrated the healthiness of their diet. But the ones who rated their diet as poor were the highest in accuracy at 97% when assessing the healthiness of their diet. The percentage of participants who could accurately assess the quality of their diet ranged from 1%-18% in the other four rating categories.
It's difficult to know if people lack an accurate understanding of what goes into a healthy versus an unhealthy diet, or if they perceive the healthiness of their diet as they would like it to be rather than what it really is.
Until there is a more complete understanding of what individuals consider when assessing the healthiness of their diet, it will be challenging to determine what knowledge and skills are necessary to improve self-assessment or perception of one's diet quality.
Further research could help explain what factors we consider when asked to assess the quality of our diet. For example, it would be beneficial to know if people are aware of particular dietary recommendations, and if they consider where their food is purchased or how it gets prepared.
Keep in mind that a healthy diet does not have to be complex. To simplify between healthy and unhealthy foods, know that foods considered healthy include fruits and vegetables, whole grains, healthy fats, lower-fat dairy products, seafood, and plant proteins. Foods that are deemed less healthy include refined grains and foods high in sodium, added sugars, or saturated fats. Starting with the basics and keeping it simple could go a long way in establishing and maintaining a healthy diet that is, if asked again, probably healthier than you think.
Sources: Science Daily, American Society for Nutrition, CDC, National Institute of Health
