Nutrition in the News: How Do Weight Loss Injections Actually Work?

Popular with celebrities, weight loss injection drugs, like semaglutide, have broken into the mainstream recently. But how do they work, and should they be considered as safe long term solutions?

The ever-evolving world of weight loss trends has taken a bit of a ‘weird’ turn recently.

Currently under the spotlight due to its recent controversial surge in demand, is the weight loss drug semaglutide (also known by the brand name Wegovy). Originally launched as a medicine to help control type 2 diabetes, it became popular with an unintended crowd endorsing it for its fat trimming capabilites. Even Elon Musk is a fan, apparently.

Here’s our nutrition team to break down the science behind semaglutide and its impact on weight loss.

What is semaglutide?

It's a type of medication known as a GLP-1 receptor analogue. In simpler terms, semaglutide mimics the effects of a hormone called GLP-1, which normally helps control our blood sugar levels and appetite. GLP-1 tells our brains that we’ve eaten and assists insulin in maintaining a healthy blood glucose level. It has become noteworthy for its promising role in weight loss.

How does it work?

For diabetes management, semaglutide prompts insulin release, curbs glucagon production (a hormone that raises blood sugar) and delays stomach emptying, improving blood sugar control.

In the context of weight loss, semaglutide stands out for its impact on appetite. It targets the brain's hunger centres, delivering a powerful signal that lets you know you're full and don’t need to eat more. Consequently, it reduces food intake by lowering appetite, slowing digestion in the stomach and reducing food cravings, leading to significant weight loss.

How do you access semaglutide?

It’s commonly administered through weekly injections and sold under brand names such as Ozempic and Wegovy and has become available on prescription in the UK for the treatment of diabetes and obesity. Obtaining semaglutide on the NHS comes with specific criteria outlined by the National Institute for Health and Care Excellence (NICE). The criteria, includes some of the recommendations below:

Should be prescribed alongside diet and physical activity support for adults with a weight-related health condition – such as hypertension or cardiovascular disease and a Body Mass Index (BMI) of at least 35, or, exceptionally, a BMI of 30, if they meet the criteria for specialist weight management services.

Are there side effects?

Like many medications, semaglutide, a gut-derived peptide, can have potential side effects. Wegovy, a medication containing semaglutide, lists nausea (most common), diarrhoea, constipation and headaches as some of the most common side effects on its website. As the research is still in its early stages, rarer side effects, both postive and negative may continue to emerge over time.

What does the research say?

Published in 2021, the initial research featured a randomised trial looking into the effects of a 68 week treatment with once-weekly semaglutide (at a dose of 2.4 mg) or placebo, plus lifestyle intervention. This primary data showed sustained weight loss over this time period with semaglutide in adults with overweight or obesity.

A follow up to this study was published in 2022, looking at the effects over a longer time frame of 2 years. The results also showed that, in adults with overweight or obesity, semaglutide improved short-and longer-term control of eating (such as craving control) associated with substantial weight loss.

While positive, further research is needed, especially when looking beyond the 2 year period, to see the long term effects and if the medication was stopped. Additionally, expanding the demographic scope would enhance the generalisability of the findings to the general population.

Final thoughts: Can it be considered a long term solution?

Semaglutide, while beneficial for managing diabetes and aiding weight loss, is not a cure. Success with semaglutide requires a holistic approach, encompassing balanced nutrition and regular physical activity. Importantly, it’s a drug for life; stopping the injections will result in a return of appetite and cravings.

This is not a quick fix or rapid solution for shedding a few pounds. Rather, it’s for those individuals facing prolonged struggles with weight. It’s crucial to remember that these medication do not tackle the route of the problem, they treat rather than prevent obesity. Despite promising indications, further research is needed to understand its long term effects.