[Estimation of energy expenditure in patients with morbid obesity]

The equations available for the prediction of basal energy expenditure (BEE) may not be applicable in morbid obese individuals since the contribution of the fat free mass (FFM) over the BEE is not constant. The aim of this study was to obtain new equations for the prediction of BEE which are specific for patients with morbid obesity.

In 26 women with morbid obesity age, weight, body composition by bioelectric impedance and BEE by open circuit indirect calorimetry were determined. The BEE observed was compared with that estimated from the previously described equations. The multiple regression method was used to obtain the BEE prediction equations.

Upon comparison of the BEE observed with the BEE estimated by the described equations a significant relation was found between both parameters. The differences were also significant except when the Harris-Benedict equation was used. Multiple regression analysis demonstrated that when the variables of body composition were included, the FFM explained 75% of the variation in BEE and on forcing the entrance of fatty mass, the explanation increased to 79%. When only the anthropometric variables were included, weight explained 69% of the variation.

In morbid obesity, most of the equations described for estimating basal energy expenditure are not applicable. New equations are reported for the prediction of energy expenditure.