Answer

Believe it or not, at one time, it was considered good to be overweight. High body-fat was seen as a sign of good health and a robust diet. That changed in the mid-20th century when insurance companies noticed that their overweight customers actually had more health problems.

The search for a way to measure healthy weight began.

The body mass index was first used under that name in 1972. It is based on the work of Belgian math expert Adolphe Quetelet, who died in 1874. Quetelet figured out that your weight should be in proportion with your height and created the formula used for BMI.