Simple estimation of ideal body weight from body mass index with the lowest morbidity.

Body mass index (BMI) is expressed by the body weight (kg) divided by height (m) squared. Therefore, if we know ideal BMI, ideal body weight (kg) of each individual can be calculated by a formula: Ideal BMI x height (m)2. In order to estimate ideal BMI, we investigated average BMI with the lowest morbidity using 4565 Japanese men and women aged 30 to 59 years. Their BMI distributed widely with the highest frequency at 23 in men and 21 in women. The morbidity was evaluated by the number of medical problems that the subjects with each BMI have. The BMI associated with the lowest morbidity was calculated to be 22.2 kg/m2 in men and 21.9 kg/m2 in women according to the quadratic regression curves derived from the relation between BMI and morbidity. From these data, we propose that an ideal body weight in Japanese is 22 x height (m)2.