Sarah is an experienced writer and editor enthusiastic about helping readers live their healthiest and happiest lives. Before joining Forbes Health, Sarah worked as a writer for various digital ...

When you go in for a wellness exam, oftentimes the first things the medical assistant does is take your height and weight. With this data, the computer spits out your body mass index (BMI) number.

BMI is an estimate of body composition based on weight and height. For people of any sex, a moderate BMI is usually 18.5 to 24.9. For people assigned female at birth, BMI does have some limitations.

Less than two thirds of adults can correctly estimate their own body mass index (BMI) and less than half can identify their own body size, according to a study of 744 Polish adults published in ...