Is it safe to follow a bariatric diet without surgery?

Simon Edward • 26 November 2024

Bariatric surgery patients eat special diets. But is it OK to follow a bariatric diet without surgery? Let's find out.

There are many different types of food on the table.

Bariatric surgery is a type of operation that can help a person lose weight. Typically, the surgery involves making the stomach smaller to limit the amount of food a person can eat.


If you have bariatric surgery, your doctor will tell you to follow a strict diet before and after the operation. These diets are essential to the success of the operation.


However, you might be wondering if it's a good idea to follow a bariatric surgery diet without surgery. Would this be a safe and effective way to lose weight?


The short answer is no. The diets that are prescribed immediately before and after surgery are very restrictive and should only be followed under medical supervision.


However, there's also a long-term diet that patients start to follow after they recover from surgery. This diet aligns with healthy eating guidelines, so it should be safe for most people to follow a version of it.


It's always best to talk to your doctor before making long-term lifestyle changes, though. They can advise on the healthiest route forward based on your needs and medical history.


Types of bariatric surgery diets


The pre-surgery (liver reduction) diet: this diet is designed to make your liver smaller so it's easier for your surgeon to access your stomach. It's very restrictive and involves eating liquid foods or a set menu of solid foods. It should not be followed without medical approval.

The immediate post-surgery diet: this diet is designed to help your stomach recover after surgery. It starts as a liquid diet and involves gradually moving to solid food over a few weeks. It should not be followed without medical approval.

The long-term bariatric diet: once patients have recovered from surgery, they follow a balanced diet based on planning meals with key food groups. People on this diet usually aim to eat between 900 and 1,000 calories per day. It should be safe to follow a version of this diet adjusted to your optimal calorie intake – but it's best to speak to your doctor first.

A bowl of food with eggs , avocado , grapefruit and cherries on a wooden cutting board.

Are there other ways to lose weight without surgery?


Yes. Overly restrictive diets are far from the safest or most effective ways to lose weight. If you want to lose weight without surgery, there are clinically proven methods you can try instead.


You can find more details in our guide to slimming treatments – but here's the quick version:


Diet and exercise: eating a calorie-controlled diet and increasing physical activity is one of the most established and effective ways to lose weight. However, it's not always the easiest.

Weight loss coaching: you might find it easier to follow a diet and exercise plan if you get help from a professional weight loss coach. This type of coaching is available privately and from some NHS primary care providers.

Weight loss drugs: several types of weight loss medications are approved in the UK. This includes Alli, an over-the-counter weight loss tablet, and prescription weight loss injections called Wegovy and Mounjaro.


SemaPen is a private healthcare provider that specialises in guided weight loss programmes using Wegovy and Mounjaro. With our treatments and a sensible diet and exercise regime, you can expect to lose 15% of your body weight on Wegovy or 21% on Mounjaro.¹


To find out if you're eligible, you can take our online consultation. You'll find out instantly if you can get a prescription.


Sources


1. Results are based on the STEP 1 Wegovy trial and SURMOUNT-1 Mounjaro trial. Results vary – weight loss can be more or less than the 15% average.


Wilding, J.P.H. et al. (2021) "Once-weekly semaglutide in adults with overweight or obesity" New England Journal of Medicine, 384(11) https://doi.org/10.1056/NEJMoa2032183

Jastreboff, A.M. et al. (2022) "Tirzepatide Once Weekly for the Treatment of Obesity" New England Journal of Medicine, 387(3) https://doi.org/10.1056/NEJMoa2206038

Mazdutide is a GLP-1 injection that works similarly to Mounjaro. Discover everything you need
by Simon Edward 1 December 2025
Mazdutide is a GLP-1 injection that works similarly to Mounjaro. Discover everything you need to know about this up-and-coming weight loss drug.
Want to know if you're eligible to take Mounjaro? Discover the threshold BMI for Mounjaro
by Simon Edward 29 November 2025
Want to know if you're eligible to take Mounjaro? Discover the threshold BMI for Mounjaro in private and NHS settings.
Is buying the cheapest Mounjaro really worth it? Learn the risks of 'bargain' options and why safe s
by Simon Edward 29 November 2025
Is buying the cheapest Mounjaro really worth it? Learn the risks of 'bargain' options and why safe support matters.
Have you heard about semaglutide tablets?
by Simon Edward 24 November 2025
Have you heard about semaglutide tablets? Let's compare Wegovy injections and oral semaglutide in terms of weight loss.
Seeing weight loss compared to objects can help you understand and celebrate your progress.
by Simon Edward 21 November 2025
Seeing weight loss compared to objects can help you understand and celebrate your progress. Visualise success with these simple comparisons.
Can Wegovy make you sleepy? Learn everything you need to know about Wegovy and tiredness
by Simon Edward 17 November 2025
Can Wegovy make you sleepy? Learn everything you need to know about Wegovy and tiredness in our guide.
We can't fix obesity without fixing the stigma associated with the disease.
by Simon Edward 14 November 2025
We can't fix obesity without fixing the stigma associated with the disease. Discover what needs to change in our culture and healthcare.
As one of the UK's biggest health challenges, obesity comes at a great cost to the NHS and others.
by Simon Edward 10 November 2025
As one of the UK's biggest health challenges, obesity comes at a great cost to the NHS and others. Learn the true cost of obesity in the UK.
It's not safe to use Mounjaro while pregnant. Learn about the risks associated with Mounjaro
by Simon Edward 7 November 2025
It's not safe to use Mounjaro while pregnant. Learn about the risks associated with Mounjaro and pregnancy.
We all know eating fruit is good for us, but what is a good fruit for weight loss? Find out how
by Simon Edward 3 November 2025
We all know eating fruit is good for us, but what is a good fruit for weight loss? Find out how fruit fits into a healthy, balanced diet.
More posts