Does the Lee obesity index measure general obesity?

Obesity, defined as increased percentage body fat, was correlated with the Lee index (weight 0.33/Naso-Anal Length) in three groups of adult rats. One group had been fed laboratory chow and served as controls. Another group had been made obese by feeding a palatable diet, and the third group made lean by a period of undernutrition during their suckling period. Although the three groups differed significantly in percentage body fat, there were no significant differences in their Lee indices. Further, the Lee index did not correlate significantly with percentage fat in any of the groups. It is postulated that the reason for the lack of correlation between obesity and the Lee index in intact rats is that length is a relatively weak predictor of fat free mass in animals of a similar age and nutritional history.