Measuring Weight Loss
Trying to determine how much weight loss a treatment can offer is confusing. Surgeons often report weight loss as a proportion or percentage of the “excess weight” weight that a person carries assuming a certain goal or ideal weight (usually a BMI of 25). People seeking treatment often want to know how this translates to themselves, as a percentage is a rather nebulous figure.
There is information on this website about how to calculate your own BMI and excess weight. But for example a person weighing 130 kg, at a height of 168 cm (5’6”), would have a BMI of 46, a goal (BMI 25) weight of 71 kg and an excess weight of 59 kg.
If this person were to loose 50% of their excess weight (30kg) they would end up at 100 kg, and if they were to loose 80% of their excess weight (47 kg) they would end up at 83 kg. The graph below shows the percentage excess weight loss, actual weight loss and BMI points lost in patients having the three different procedures mentioned above over 24 months.
Average Excess Weight Loss Over Time