OBJECTIVE:

To study the prevalence of overweight (BMI > 27 kg/m2) and major life-style determinants of energy balance in Finland, in 1982 and 1992.

DESIGN:

Cross-sectional study.

SUBJECTS:

640 men and 677 women in 1982, and 664 men and 765 women 1992.

MEASUREMENTS:

BMI, dietary intake (3 d food record), physical activity and energy expenditure (self-administered questionnaire), data on smoking and educational status.

RESULTS:

The prevalence of overweight men was 39% in 1982 and 43% in 1992, and of women 33% and 34%, respectively. In 1992, the reported daily energy intake was 1203 kJ lower in men, and 711 kJ lower in women, compared with 1982 (P < 0.001). When suspected underreporters (energy intake less than 1.28 x BMR) were excluded, the decrease in reported energy intake was only 519 kJ (men) and 347 kJ (women) (P < 0.01). In 1992, the total physical activity level was 3.0% lower in men (P = 0.002), but only 0.6% lower in women (P = 0.18). Between 1982 and 1992, energy expenditure during work (P < 0.03) and during moving to and from work (P < 0.002) decreased. In contrast, energy expenditure during leisure-time exercise activity increased in men (+113 kJ/d) and in women (+146 kJ/d) (P < 0.001).

CONCLUSION:

Underreporting may explain a major part of the observed decrease in reported energy intake in 1992. The decreased energy expenditure during work was not counterbalanced by increased leisure-time physical exercise.