LOSS is a pragmatic clinical evaluation of intensive medical approaches to weight loss for
individuals with extreme obesity (body mass index [BMI] 40-60 kg/m2). The intensive medical
treatment is designed to produce 25% weight loss from baseline and to maintain at least 20%
weight loss from baseline. The intensive medical treatment is compared to a usual care
treatment model where individuals utilize self directed approaches to weight loss. The active
treatment period is three years, followed by two years of observation.