Extent and determinants of discrepancy between self-evaluations of weight status and clinical standards

To examine the extent and type of discordance between personal and medical classifications of weight status, and to examine the influence of sociodemographic factors on the misclassification of weight status.

The 1991 Health Promotion and Disease Prevention Supplement of the National Health Interview Survey, a nationally representative, cross-sectional survey of the U.S. population.

Adults 18 years and older (N = 41,676).

Respondents' self-evaluations of weight status were compared to classification of their body mass index (BMI) by medical standards. Twenty-nine percent of respondents incorrectly classified their weight status relative to medical standards, and the nature of this error was variable. While 27.4% of overweight persons judged their weight to be "just about right," of those who did judge themselves to be overweight, 23.9% were in fact normal or underweight according to their BMI. Overall, 16.6% of persons underassessed their weight category, and 12.4% overassessed their weight category. Multivariate analysis revealed that sex, age, race, income, education, and occupation influenced the misclassification of weight status.

A substantial proportion of Americans deviate from medical standards in their self-evaluations of weight appropriateness, and this lack of correspondence may reflect the normative judgments of various population subgroups. Clinical and public health programs that employ a uniform strategy or approach to the population may not be efficacious.