Pitfalls in using BMI as a selection criterion for bariatric surgery

Abstract

Because obesity was thought to be an important independent predictor for mortality, the eligibility criteria for bariatric procedures are all indexed to some minimum level of BMI. Recent evidence suggests that BMI is a poor correlate of mortality, suggesting that BMI should not serve as the basis for bariatric surgery approval. Longevity studies of patients who have undergone bariatric operations have shown either a little or no improvement in survival. The distribution of fat is a far greater predictor of complications of obesity then the degree of obesity itself. When excessive amounts of calories are deposited into muscle it causes insulin resistance and diabetes. Consequently, weight loss induced by any means is an extremely effective treatment for obesity-related diabetes. BMI is used as a criterion for bariatric surgery because it was thought that weight loss would be associated with greater longevity. This is not been the case and BMI should no longer be used to select patients for bariatric procedures. Bariatric operations should be offered to patients with complications of obesity that would be expected to resolve with weight loss such as diabetes.