Van de Laar recommended percentile-based charts based on large numbers of patients from multiple surgeons and centres with essentially good follow-up data [5]. He implied that percentile charts are neutral and can be based on different characteristics such as gender, age or baseline BMI. However these percentile charts are scarcely found in the literature.

The relationship between BMI and mortality is U-shaped and hence believed that body fat mass is a better measurement of outcomes. The use of BMI as a proxy for the measurement of adiposity can be misleading as body weight is the sum of individual organs and tissues including adipose tissue, skeletal muscle mass and organ mass. In addition, BMI does not convey any information on fat distribution in the body [6].

Bioelectric Impedence Analysis (BIA) is one of the available direct measurements of body fat [7–9]. Clinical studies have validated foot-to-foot BIA technology for body composition analysis [10]. National norms for BIA differences between ethnic and racial groups based on NHANES111 have been published recently. Studies on fat mass show a direct linear relationship between body fat and all-cause mortality [11].

The metabolic effects from weight loss should also be considered in defining success of bariatric surgery. Now that metabolic benefits of bariatric surgery are well recognized, bariatric success should be redefined to include the metabolic parameters [5]. It is well documented that small amounts of weight loss carry significant health benefits and perhaps individual co-morbid conditions should be measured as parameters of successful outcomes following bariatric surgery. These should importantly include type 2 diabetes, dyslipidemia and hypertension.