Misperception of body weight among overweight Danish adults: trends from 1995 to 2008

Objective: To examine changes in the prevalence of overweight and weight misperception among overweight Danes from 1995 to 2008, and to identify factors associated with weight misperception. Design: Cross-sectional studies, in which data on self-reported weight, height and self-perception of overweight status were obtained through face-to-face interviews. 'Overweight' includes obesity. Weight misperception was defined as overweight individuals who did not perceive themselves as overweight. The chi(2) test was used to analyse changes over time and multiple logistic regression analysis was applied to identify factors associated with weight misperception. Setting: The Danish National Survey of Diet and Physical Activity in three periods: 1995, 2000-2004 and 2005-2008. Subjects: A random sample of 9623 Danes aged 15-75 years. Results: The prevalence of overweight increased in men and women from 1995 to 2005-2008 (from 35.1% to 43.0%, P<0.001). Concurrently, there was a reduction in the proportion of overweight men (from 77.5% to 71.4%, P = 0.001) and women (from 54.8% to 51.9%, P = 0.24) who misperceived their weight. Factors associated with weight misperception were 'never intend to eat healthily' (men), high levels of leisure-time physical activity, 'very good/excellent' self-rated health and survey year (higher misperception in 2000-2004 than 2005-2008; P < 0.05). Conclusions: The increase in overweight from 1995 to 2005-2008 was accompanied by a reduction in the proportion of overweight men misperceiving their weight. This may indicate that more men see overweight as a personally relevant health problem. Our findings also suggest that overweight individuals who are more physically active and have better self-rated health may not consider their excess weight a health problem.