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 χ 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.