Evaluation of validity of five weight-height obesity indices.

Validity of five weight-height obesity indices, Broca-Katsura index, weight/height ratio, BMI, Rohrer index and Benn index were evaluated as an obesity index in male medical students of Kyushu University. Validity of them was evaluated using the following three criteria: (1) it should be highly correlated with body weight and its distribution should be independent of height; (2) it should be highly correlated with obese rate to the standard body weight of Japanese young men; (3) it can accurately classify individuals as overweight or not overweight. BMI met all three criteria in this population. Benn index proved to be not only independent of body height but also highly correlated with body weight and obese rate, though we could not evaluate this obesity index using criterion (3) because there is no generally-accepted cut-off point of overweight of it. Broca-Katsura index, weight/height ratio and Rohrer index were not independent of body height. From these results, it is concluded that BMI is the best weight-height obesity index in this population.