Overweight and obesity are measured using BMI (Body Mass Index). BMI is calculated as weight divided by height multiplied with height in cm. BMI. BMI is calculated on basis of self-assessed information on height and weight.

BMI does not distinguish between fat and muscle mass.

Statistics Norway uses the cut-off points recommended by WHO-EURO: Underweight (BMI<18.5), some overweight (BMI 25-26.6), overweight (BMI 27-29.9), obese (BMI >= 30).