Obesity is defined as excessively high ratio of fat relative to total body weight. The Body mass index (BMI) measures the weight to the height ratio and defines the degree of obesity. The Body mass index equals body weight in kilograms, divided by the square of body height in meters. For example, an individual of 1,60 meters in height and 105 kilograms in weight has the following body mass index: BMI=105/(1,60 x 1,60) = 41.

The BMI defines the degree of obesity according to the following table:

BMI value                Body weight and morbidity

Lower than 18         Underweight

18-25                         Normal

25-30                         Overweight

30-35                        Obese

35-40                        Severely obese

Over 40                     Very severely obese

Individuals with a BMI over 50 are considered  super-obese.

Calculate your own BMI:

Weight (kg)

Height (cm)

Enter your weight in kilograms and your height in centimeters and then select OK.

The Body mass index is not the only index for determining obesity. Accurate data can only be derived by body fat measurement, which measures the exact body fat ratio as well as indicates the net musculoskeletal weight, total body liquids, fat distribution in different body parts, muscular tissue distribution, and the basic metabolism in calories.

From these data several interesting indexes can be derived, such as the Percent Body Fat (PBF), with a normal range between 18 and 28, and the Waist-Hip Ratio (WHR), with a normal range between 0,75 and 0,85.

The PBF is undoubtedly the most accurate indicator of obesity considering that is based on direct measurement of body fat. The WHR is an indicator of the contribution of abdominal fat to the obesity. This aspect is quite significant as a BMI 40 obesity for example is much more dangerous if it is based on a fat distribution around the middle of the body (abdominal fat), compared to a BMI 40 obesity based on a fat distribution around the hips and the limbs.