One of the most frequently asked questions about bariatric surgery is how successful the procedure is expected to be. Comparing the success rates of different procedures can help you to decide which one is right for you, but it’s important to understand what these figures actually mean. How is the success of a bariatric procedure measured and what does the average success rate mean for your weight loss?

How is Success Measured?

The most common measure of success after bariatric surgery is the percentage of excess weight that is lost. When you see these figures quoted by weight loss clinics, you will be looking at an average for all patients who had the procedure. The weight loss figures will usually be for the first 1-2 years after the surgery. Weight loss is usually most rapid during this period, but it will then continue more solely afterwards as long as you continue to watch what you eat.

However, it is important to remember that these figures are averages, so there is no guarantee that you will achieve this amount of weight loss. You might lose weight more slowly or start putting the weight back on if you stop following your diet. However, you could also find that you lose weight more easily than other people.

It is also important to realise that success after weight loss surgery is about more than just this one number. The amount of weight that you lose is important, but you should also judge your success according to:

• How well the procedure and your recovery went
• Any improvements in your health, for example in the symptoms of type 2 diabetes
• Whether you feel happier and healthier after the procedure
• If you are able to make permanent changes to your lifestyle and maintain the weight loss in the long term

Most people who have bariatric surgery will lose a significant amount of weight and keep it off in the long term. Although about half of all patients will end up re-gaining a small amount of weight (about 5% of what they lost), most will be much thinner and healthier in the future. Approximately 80% of patients will consider the surgery a success as they will achieve long term weight loss and feel better.

How is Weight Loss Calculated?

The success rate for bariatric surgery is calculated as the percentage of excess weight that is lost. We use the average amount lost to compare the success rates for different procedures. We can also look at your personal weight loss to determine if the procedure was a success for you. In order to do this, we need to know what your ideal weight should be.

Your ideal weight will be calculated according to the normal BMI (Body Mass Index) for someone of your height. You can work it out by multiplying your height in metres by itself and then multiplying this number by 25. This is the weight in kilograms that would give you a healthy BMI of 25.

In order to find out how much excess weight you’re carrying, all you need to do is subtract this ideal weight from your current weight. We will do this before you have the weight loss procedure so that we know how much weight you need to lose. You will then be able to keep track of your weight after the surgery to monitor the progress.

The percentage of excess weight that you have lost can be calculated by dividing the amount of weight you have lost by the amount of excess weight you were carrying at the beginning and then multiplying this by 100. If you have lost at least 50% of your excess weight by the end of the first year, then your weight loss surgery will be considered a success.

Success Rates for Bariatric Procedures

If you’re considering bariatric surgery, then you may be wondering what you can do to increase your chances of success. One of the biggest decisions you’ll have to make is which type of bariatric procedure to have. Since each operation affects you differently, the average weight losses are different for each procedure.

You can expect to lose the following proportions of your excess weight within the first two years, on average:

• 50% with a gastric band
• 50-60% after a sleeve gastrectomy
• 60-70% for a gastric bypass

Although it can be tempting to opt for the procedure with the biggest expected weight loss, it is important to compare the risks and benefits of each choice. The gastric bypass can produce the fastest weight loss, but it is also the most invasive procedure, so it won’t be right for everyone.

What Affects the Success Rate?

Knowing the average success rates for each bariatric procedure can help you to make the right choices about your care, but it is also important to be aware of the factors that could affect your weight loss. Understanding these could help you to improve your chances of success after bariatric surgery.

• How well you stick to your diet after the procedure will have a big impact on its success. If you follow your doctor’s recommendations, then you should start losing weight quickly within the first six months.
• How much physical activity you do will also influence your weight loss. You should try to gradually increase the amount of exercise you do, according to your doctor’s advice in order to improve your health and lose more weight.
• Individual differences can also affect your weight loss as everyone responds differently. It’s impossible to predict these differences.

Since so many different factors can influence your weight loss, the average success rates can’t tell you exactly how much you will lose. You will get a more accurate prediction from your bariatric surgeon when you meet to discuss the options. The doctor can help you to work out how much weight you need to lose and will ensure that you have realistic expectations of what each procedure can accomplish.