One of the most common questions from patients considering weight loss surgery is “So… how much weight will I lose?” Unfortunately, this isn’t a question with a quick and easy answer. The shortest answer we can give is “it depends.” If you are 45 years old and only suffer from obesity but otherwise active and able to perform challenging physical tasks then you will be able to lose more weight than an older patient who has severe osteoarthritis of the knees and cannot be as active. We have also found that two patients may be very similar, if not identical, and they may have slightly different weight loss. Which translates into, there is also a genetic component of how much your body is willing to lose weight after the surgery. The good news is that the vast majority (over 95%) of patients will lose a significant amount of weight in the first 6-12 months.
The goal of bariatric surgery is to decrease the amount of excess weight you carry. So, there are several factors which will determine how much weight you will lose after surgery. To simplify the complexity of the topic we will focus on THREE factors.
If your pre-op BMI is in the lower range of clinical obesity, the amount of weight loss you can expect may be considerably less than someone with a much higher BMI. Let’s say you have 200 lbs of excess body weight and your friend has 150 lbs of excess body weight. You both decided to have laparoscopic sleeve gastrectomy done and you both lose 100 lbs. you both lost similar amounts of weight; you may still have more excess body weight. So, to level the playing field we tend to talk about the percentage of excess body weight.
Because each patient is unique, each patient’s goals and ideal weight loss will differ. Despite the “normal weight” clinical BMI recommendation being from 18-25, some patients find that it doesn’t feel ideal to them and choose to target a different mark. This is because the BMI does not take gender and muscle density considerations into account. For example, a bodybuilder may have a BMI that suggests obesity even if they are clearly not obese. Furthermore, experience taught us that dropping from a very high BMI to a normal is very difficult. But, let’s say you drop from a BMI of 45 or 50 to a BMI of 28-30, even though that’s a higher than desired BMI you will get significant health benefits from this drastic weight loss.
The number of lbs you lose doesn’t always relay the entire picture of how you feel and the health benefits you gain from losing the excess body weight. Patients with severe arthritis of the knee repeatedly tell me on their first post-operatively visit how great they feel after the surgery, when they have only lost 15-20 lbs. The reason for that is weight loss has a multiplying effect. For every 1 pound of weight loss 4 pounds of pressure is unloaded from the knee and hips joint. So, when someone loses 15-20lbs 60-80 lbs of pressure is unloaded from their knees/hips and lower back!
Some procedures have a greater capacity for weight loss than others in the initial months after surgery. Generally, weight loss potential in the four main bariatric surgery procedures ranks from Lap-Band, sleeve gastrectomy, gastric bypass, then biliopancreatic diversion with duodenal switch (known as the switch for short) from least to greatest. With a gastric banding procedure you can expect roughly 15-25% Excess Body Weight Loss at 1 year and 20% at 2-3 years. Estimated weight loss with the gastric sleeve is 55-60% of excess body weight at 1-2 years. Most gastric bypass patients will lose around 65-70% of their excess weight at 1-2 years. Whereas switch patients can lose up to 90% of their excess body weight at 1-2 years.
Due to a combination of lower or excess body weight loss potential and increased risk of longer-term complications, we no longer perform gastric band surgery. Multiple research papers have shown that only 15-20% of patients can keep their excess body weight loss and the complication rate is unacceptable in terms of nausea/vomiting and hardware complication. For example, infect, erosion, slippage of the band etc. We believe there are safer and more effective treatment options available nowadays that it’s time for us to move on from the old and unsuccessful gadgets of the last millennium.
Research shows, in the long-term, weight loss trends for stapled procedures like the gastric sleeve and gastric bypass are similar over the long term. But remember, there are many reasons other than weight loss to choose one procedure over another. For many, issues like chronic reflux, diabetes, age, dietary restriction or a high stress lifestyle come into play. The procedure with the highest weight loss and the lowest recidivism (gaining your weight back) is the biliopancreatic diversion with the duodenal switch.
Weight loss surgery patients have many goals, not all focused only on weight. Bariatric surgery can aid patients in diabetes remission, relieving joint pain, or being able to participate in activities their weight or size prevented before. Success in bariatric surgery is often clinically measured as at least 50% of your excess weight lost and maintained for five years, but for every patient, the goals are unique. Working closely with our bariatric care team and sharing your goals with those who support you can help you reach them sooner.
If you are worried about what you have heard about weight regain, statistically, most patients will regain 5-10% of their excess weight as they adapt to their procedure and they become less strict with the lifestyle changes they made early after their procedure. When you look at the grand scheme, regaining 5 to 10 pounds after losing, say 100, still means you are 90 lbs lighter than when you started…no need to flinch!
Remember weight loss is a journey and not a destination. Make sure you enjoy the journey and benefits you reap from it.