People significantly underestimate the amount of activity they do according to a Norwegian study. However, it’s not BMI which causes people to exaggerate, but sex, age and education.

The study, Comparison of Self-reported versus Accelerometer-Measured Physical Activity, assessed 1,751 people from 19 to 84 years, in 10 regions of Norway. Of these, 47 per cent were overweight or obese.

Each participant used an accelerometer to measure their activity levels, as well as filled in a questionnaire to estimate how much they had done.

The difference between self-reported and measured sedentary time and vigorous intensity physical activity was greatest among men with a lower education level and for men 65-years and over.

Although men reported 47 per cent more moderate to vigorous physical activity than women, there was no difference between the sexes in the accelerometer findings.

The study showed men were more likely to exaggerate than women: they reported 56 additional minutes of walking and moderate exercise than the accelerometer showed, while women reported an extra 52 minutes.

Men reckoned they had spent 439 minutes sitting around, compared with 565 minutes shown by the accelerometer and women guessed at 401, compared with 535 minutes.