The Body Mass Index (BMI, or Quetelet Index) is a convenient way of representing relative body weight and is calculated by taking the body weight in kilograms (kg) and dividing it by the square of the body height in meters (m). Based on the BMI, weight can be classified as normal weight, underweight or overweight. With normal weight, the BMI is between 18.5 and 25 kg/m². A BMI of less than 18.5 kg/m² is considered underweight and a BMI of more than 25 kg/m² is regarded as overweight. For young people aged 15 to 18, the age and gender-specific threshold values of the Flemish growth curves are used to break down the BMI in categorical terms.
How tall are you, without your shoes on?
Are you currently pregnant?
Yes/No
If the subject was pregnant, the following question was asked:
How much did you weigh without clothes and shoes before your pregnancy?
In all other cases:
How much do you weigh without clothes and shoes?