The Decision to Have Weight Loss Surgery

Should you get weight loss surgery? This question can be difficult to answer. Obesity is dangerous, and surgery works far better than any other weight loss method, but there are associated risks, and not everybody is successful after surgery. So how do you decide?

The bottom line is that surgery can work great to help you lose weight and keep it off if you do your part. The decision to have weight loss surgery, then, should be based upon you understanding and accepting the role you play in your long-term success after surgery.

To understand the role you play, you first need to understand what surgery does, and more importantly, what surgery does not do.

Over the past several years we have made impressive progress in better understanding how weight loss surgery really works. We used to think it was all about mechanical restriction – that is, forced portion control. This is part of how weight loss surgery works, particularly early after gastric sleeve and gastric bypass surgery, but we have learned that there is much more to it.

We know now that surgery primarily works by altering biologic processes in the body that are involved with weight regulation. To understand what surgery really does we first need to understand how weight regulation in the body normally works.

The first point to make is that human biology is actively engaged in weight management. This should come as no surprise since having adequate stores of energy (fat) is important for the preservation of life. The goal of this biologic weight management system is to maintain body weight at some set-point weight. The problem in obesity is that the set-point that the body’s weight regulatory system works to maintain is too high.

It is useful to think about the functioning of the weight regulatory system in terms of what happens when weight loss occurs, and what happens when weight gain occurs.

Weight Loss

The body weight regulatory system strongly opposes weight loss. Weight loss prompts a strong reactionary response by the body that serves to achieve weight regain back up to the biologically desired set-point weight. Everyone who has ever tried to lose weight is familiar with this reactionary process – an increase in hunger and appetite, and a decrease in metabolic rate. Everyone who has ever tried to lose weight is also familiar with the usual outcome of this reactionary process – weight regain.

Weight Gain

The body weight regulatory system does not do nearly as good a job at preventing weight gain as it does at preventing weight loss. Even more problematic is that when weight gain occurs, the set-point tends to reset higher. The body weight regulatory system then works to defend this new, higher set-point weight. The result is that people end up trapped at their highest weight.

Of note there is considerable variability between people in how the body weight regulatory system works regarding weight gain. Susceptibility to weight gain and the ability of the set-point to reset higher are determined by genetics – some people are much more prone to weight gain than others.

Weight Loss Surgery

Weight Loss Surgery works by changing the biology that blocks weight loss. The GI tract, we have learned, is an important part of the biologic system that so effectively prevents weight loss. Surgery, by changing the GI tract, changes how this system works. Instead of opposing weight loss, the altered control system causes weight loss (sleeve gastrectomy, gastric bypass) by resetting the set point lower – see the blog post Weight Loss Surgery Changes The Body Weight Set Point.

What surgery doesn’t do is change the biology of weight gain. This means that the factors that caused weight gain previously can cause weight gain again. This is the fundamental thing to understand when trying to decide whether or not weight loss surgery is a good choice. If the factors that caused weight gain to occur aren’t changed, weight gain can occur again.

The two factors that interact to cause weight gain are genetics and eating habits. Genetics determines susceptibility to weight gain when excess calories are consumed, and eating habits determine calorie intake. Surgery does not change a person’s genetic susceptibility to weight gain, and surgery does not prevent a person from eating too many calories.

Consider this – when patients gain weight back after weight loss surgery the typical rate of weight regain is about 10 pounds per year. Over many years this can add up, but the point to understand is that the rate of weight regain is slow. Ten pounds per year is only 100 excess calories per day. It is very easy to consume 100 extra calories per day after any of the weight loss operations.

So the ultimate key to permanent weight loss after surgery is establishing eating and exercise habits that will not cause weight regain. In other words habits that will enable you to not eat too many calories.

Weight loss surgery is like a big do-over – it resets your body weight set-point lower (sleeve gastrectomy, gastric bypass) giving you the opportunity to maintain a lower weight long-term. It is up to you to maintain your new lower set-point and not let it go back up again over time.

What are the appropriate eating habits after surgery? Basically the healthy habits that are recommended for everyone – regularly spaced portion controlled meals consisting of primarily healthy foods such as lean protein, vegetables, fruits, low fat dairy, and whole grains.

If you are committed to establishing healthy habits, the decision to have weight loss surgery can be a great decision, because long-term weight loss success, improved health, and a longer life are all attainable outcomes.

Read more about Dr. Oliak and his Orange County weight loss surgery program at

More Weight Loss Surgery Resources


David Oliak, M.D.

Dr. Oliak is a board-certified, fellowship-trained surgeon who specializes in minimally invasive (laparoscopic and robotic) weight loss surgery. He has been in practice in Orange County, California, since 2002, has completed more than 3000 weight loss operations, and has a track record of excellent patient outcomes.*

Dr. David Oliak is the founder of the Oliak Center for Weight Loss. He started the Oliak Center because he wanted to provide weight loss surgery done right. His commitment has always been to provide the kind of care that he himself would want to receive. Dr. Oliak is affiliated with only the best bariatric hospitals and surgery centers in Los Angeles County and Orange County.

* Individual patient results vary. Past performance is not a guarantee of future results.

Which weight loss surgeon is right for you?

Download this guide of questions to ask your weight loss surgeon to help make the best decision for you.