Body Mass Index is a calculation that was developed by insurance companies to predict increases in getting sick. The calculation is based simply on height and weight. Your weight (in kilograms) is divided by your height in meters squared.

BMI categories defined by the US Heart, Blood, and Lung Institute are as follows:

• Underweight = less than 18.5
• Normal = 18.5 – 24.9
• Overweight = 25 – 29.9
• Obese = 30 or greater

There is however controversy about BMI calculations because they don’t take into account atheletes or well muscled people. Atheletes and well muscled people tend to come out as overweight even though they may not carry that much fat as a percentage of overall body weight. An example would be Arnold Schwarzenegger – using BMI, he is considered overweight.

BMI is only one tool that you can use to determine overall health. Waist measurement and waist-to-hip ratio are also very good at helping to determine if someone is considered overweight.