How Americans Rate Their Diet Quality: An Increasingly Realistic Perspective
by Christian Gregory
, Travis A. Smith, and Minh Wendt
Economic Information Bulletin No. (EIB-83) 23 pp, September 2011
What Is the Issue?
An obstacle to policies aimed at improving diets through education is that consumers tend to overrate the quality of their diets and to think that dietary guidelines are directed at others, not themselves. In this study, we look at the change in Americans' subjective perceptions of their diet quality between 1989-91 and 2005-08. These changes provide a snapshot of consumers' increased dietary realism and, perhaps, receptiveness to dietary guidance, and they also suggest the possibility that a changed information environment has affected consumers' perception. In addition, we use data from the ERS-supported Flexible Consumer Behavior Survey (administered with the National Health and Nutrition Examination Survey (NHANES)) to highlight how perceptions of diet quality vary with food expenditures, household food availability, and eating behavior.
What Did the Study Find?
Although the actual healthfulness of diets has not changed much in the last 15 years, there has been a large and significant decrease in the percentage of Americans who rate their diets as Excellent or Very Good.
• The share of people who said that their diets were excellent or very good declined by 9.1 percentage points, from 41 percent to 31.9 percent, between 1989-91 and 2005-08.
• Declines in the share of excellent or very good self-ratings of diet were especially large among Hispanics and people who were underweight, overweight, or obese, younger than 65, or had some college education (but not a college degree).
• People who perceived themselves as overweight became less likely to rate their diet as excellent or very good between 1989-91 and 2005-08.
• Those who had diets high in fat were much less likely to rate their diets as very good or excellent in 2005-08 than in 1989-91.
These results suggest a reduced optimistic bias in Americans' views of their diets-and perhaps greater receptiveness to information about the relationships between diet and health.
We also find a strong relationship between diet assessment and some dietary choices and habits. Comparing subjective ratings of diet quality across different groups, we find:
• Self-ratings of diet healthfulness tend to be low among people who report a higher share of their food budget spent away from home and of calories eaten away from home.
• Those with better diet self-ratings are more likely to share meals with the family, both at home and away from home.
• Those who report high diet quality are more likely to keep skim milk and dark green vegetables on hand in the household, and they are less likely to stock sugar-sweetened beverages.
How Was the Study Conducted?
The data for our comparisons of diet quality perception come from the 1989-91 Continuing Survey of Food Intakes of Individuals (CSFII) and the 2005-2006 and 2007-2008 waves of the National Health and Nutrition Examination Survey (NHANES). The CSFII is also our source for data on household food expenditures in 1989-91. The 2007-08 NHANES data on diet quality perceptions, food-away-from-home frequency, household food expenditures, the kinds of food kept at home, travel time to the grocery store, and social context of eating come from the Flexible Consumer Behavior Survey (FCBS) module sponsored by the Economic Research Service. The 2005-06 NHANES included a subset of FCBS questions, including diet quality perception and food-away-from-home frequency. For these questions, we report results from the combined 2005-08 NHANES data.