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Ask an Expert: Weight loss surgery vs medication – pros and cons

“Plan for GPs to offer NHS patients Wegovy weight-loss jab, ran the headline on the BBC today, with Prime Minister Rishi Sunak stating that it could be a “game-changer” as he announced a £40 million pilot scheme to increase access to specialist weight management services. 

More than 12 million adults in the UK are considered obese and this puts a huge strain on an already ‘thinly stretched’ NHS, so a weight loss solution that does not put further pressure on our healthcare system is of course welcome news on the face of it, but how does this medication work? And is it an effective alternative to surgery? 

In this week’s expert article, Streamline Director and Leading Bariatric Surgeon, Guy Slater, discusses the considerations when comparing weight loss medication to surgery and the ‘pros and cons’ of both options. 


Weight loss surgery vs medication, Guy Slater

As weight loss experts, we are often asked to compare the medication that is now available to support weight loss, with surgical intervention. The most important point with this question, and the medication itself (Wegovy and Saxenda®), is to be clear that this is the first time in my 20-year career that we’ve had effective drugs for weight loss, and both Saxenda® and Wegovy can be very useful adjuncts to a diet.  

However, when it comes to comparing this medication to surgery, there are several points that need to be considered: 

  • The total weight loss that you can achieve with drugs versus surgery 
  • the permanency of that weight loss 
  • The risk of side effects with drugs compared to the risk of complications with surgery


So, lets talk about these points in detail.

The total weight loss that you can achieve with medication vs surgery

It will come as no surprise that both medication and surgery essentially work by controlling appetite. The medications such as Saxenda® and Wegovy do this by mimicking a natural hormone called GLP-1 which is important in blood sugar control, but also makes you much less hungry and much less interested in food. Surgical interventions work in different ways depending on the procedure but again, in hormonally induced ways.  

On average, with medication, you can expect to lose 10-15% of your body weight. So, for a typical 20 stone person coming to see me in clinic, they can expect to lose 2 or 3 stone with medication. However, with surgery the results from the National UK Audit show that those patients will lose 30% with the sleeve gastrectomy and probably 35% with a gastric bypass, which is 6 and 7 stone respectively.


The permanency of each weight loss solution

With that in mind, the weight loss you can achieve with surgery is significantly higher than with drugs. And clearly, it’s important when making your decision in terms of the permanency of each solution. A surgical intervention is proven to give very good long-term results 10-20 years out from surgery, whereas medication is very much a temporary intervention. 

Both Saxenda® and Wegovy must be injected (Saxenda® each day, Wegovy once per week) and as soon as you stop using the medication, your appetite returns and most patients will regain the weight that they have lost, unless they’re good at old fashioned dieting. However, the reality is if most patients were good at dieting, they wouldn’t be looking at alternative measures such as medication and I wouldn’t have specialised in weight loss surgery. 

The reason most people struggle with diets is that the evidence very much shows that dieting just doesn’t work and the reasons for that really are around appetite. We have biologically evolved to survive famine, not to live in times of plenty. When you diet, your body doesn’t see this as a healthy intervention but as a famine. As a result, this makes you go looking for food and it’s beyond almost everyone to maintain control of their appetite indefinitely and that’s why dieting doesn’t work.  

On the contrary, the main reason why medication and surgery have good results is by controlling appetite, allowing you to work with a reduced calorie intake.


The side effect of medication and weight loss surgery

Saxenda® and Wegovy have been used for many years in diabetic patients and they have very few side effects. If you do find side effects that you can’t tolerate, you just stop the medication and you’re back to normal – whereas surgery is a much bigger undertaking with potential, albeit uncommon, complications. 

So, medication is generally speaking the more straightforward option. In my experience, patients who are considering surgery normally know when the time is right to have surgery. If at this time you’re not quite sure, then maybe right now isn’t the correct time. In that situation, medication might be a good option; buy yourself some time, see how you get on with it, lose two or three stone in weight and maybe it will end up being a good long-term solution for you.

In summary, both medication and surgery are good solutions for weight loss. It’s really a matter of making the right choice for you given where you are in your life. And that’s where we can support you in ensuring sure you make the right decision for you.

To enquire with Streamline about the weight loss procedures we offer, please call 0333 016 3030 or fill in the online enquiry form below.

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