The Weight Loss Jab: Should I or Shouldn't I? What you need to know.

GLP-1 (glucagon-like peptide-1)agonist medications like Wegovy, Mounjaro and Ozempic have gone from diabetes treatments to household names in the space of a couple of years, and while for many they provide considerable health benefits including weight loss, there are also serious risks to long term health to consider.

Over the summer I completed postgraduate training in supporting my clients alongisde or instead of these weight loss medications. I also participated in the brilliant Weight Loss in Practice conference in London, hosted by Enzyme Science, where we analysed and discussed the latest research in how to optimise hormones and metabolism in weight management. Here's what I think you need to know.

How they actually work

These medications mimic a hormone called GLP-1, which helps regulate appetite and blood sugar. In simple terms, they turn down hunger signals and help you feel fuller for longer so you eat less. They also improve how your body handles insulin, which reduces the blood sugar swings that often drive cravings.

That's powerful, but that's not the whole story. These medications slow down the digestive process which can result in bloating, nausea, increased fermentation of foods higher in the gut leading to long term gut health issues, inflammation and thus poor nutrient absorption. With slow motility, gastric juices like bile may be sitting still rather than moving through the gut as they are designed to. This increass the risk of gallstones and more rarely, pancreatitis which is can be life threatening. Reduced appetitie generally results in less food intake, less variety and this negatively affects the health of the gut microbiome which is essential for all aspects of health, including metabolism and weight regulation.

This is why proper monitoring and support with nutrition and lifestyle still matter so much alongside these medications.

Muscle power

Here's the part that doesn't get talked about enough. Between 25- 40% of the weight lost on these medications comes from muscle, not just fat. That matters, because muscle is what keeps your metabolism moving, supports blood sugar control, and protects you as you age. This is especially significant for women during menopause. Lose muscle without replacing it, and you can end up in a worse metabolic position than when you started, especially if the weight creeps back on as fat once the medication stops.

Research shows that without proper nutritional support, people who lose weight while taking weight loss medications regain 60% of the weight they lost within one year after stopping the medication, and back to starting weight after 1.5 years (West et al., 2026).

You may have experienced this weight regain after years of restrictive dieting without the medications, and, frustratingly,  you may have ended up heavier than when you started!

Why does this happen?  The answer lies in understanding your own metabolic profile and what is going on inside YOUR body! If you have lost 40% of your musctle mass, then stop the medications or a restrictive diet without having changed your eating habits, addressed hormones and nervous system imabalance, the weight will come back fast.

My evidence based approach to guiding you through personalised weight loss management is about aiming to achieve metabolic health. Weight loss will then be a natural consequence without the medication AND it will be sustainable.  Instead of focusing on eating less, and monitoring weight, the focus is on eating better and changing your body composition.

Here are a few practical points worth knowing that apply to you whether you're considering these medications, already taking them or want to lose weight without the meds.

Before you begin

Check cardiometabolic markers, hormone levels including thyroid and check nutrient status. All of these affect how efficient your metabolism works. If there is imbalance, these factors may be working against you. Addressing imbalance before you begin can be the game changer. You want to nurture your whole body to support a healthy metabolism and weight so that it does not become a lifetime uphill struggle.

What else moves the needle

Here are a few essential foundations worth adressing whether you're considering these medications, already taking them or want to lose weight without the meds:

• Gut health. A diverse, fibre-rich diet feeds the bacteria that influence appetite, cravings and fat storage. Think beans, lentils, oats, vegetables and seeds. Aim for variety, not just your usual five.

• Blood sugar stability. Pairing protein and fibre with every meal slows digestion and smooths out the glucose spikes that trigger cravings and energy crashes. A short 10 minute walk after meals can lower the blood sugar spike and help you use up energy from the meal to reduce the amount stored as fat.

• Protect muscle. Depending on your body weight and composition, you may need between 1g and 2g protein per kg of body weight. This varies between individuals so get advice from a nutritional therapist who can help you look at what is happeing in your body and get this number right. Focus on resistance training to maintain muscle mass and protect your metabolism.

• Sleep and stress. Poor sleep and chronic stress both interfere with the hormones that control hunger and fullness. Even small, consistent improvements here can shift how your appetite behaves. If you don't address the nervous system, you will struggle to lose weight and keep it off.

• Avoid ultra processed food which contains hiddensugars and chemicals that bypass appetite regulating hormones and contribute to inflammation. (Inflammation contributes to reduced insulin sensitivity).

• Build a plan for after you come off the medications or achieve your desired weight in order to sustain the benefits for life

  
  

Weight-loss medications can be a genuinely helpful tool for the right person, but they work best alongside nutritional support. Supporting your gut, stabilising your blood sugar, protecting your sleep, monitoring nutrient and hormone status and keeping your muscles strong will always be worth doing, whether or not medication is part of your journey.

If you'd like support building a plan around any of this ,with or without medication, that is exactly what functional testing and personalised nutrition work can help with.

Hashimoto, K., Dora, K., Murakami, Y., Matsumura, T., Yuuki, I.W., Yang, S. and Hashimoto, T. (2025) 'Positive impact of a 10-min walk immediately after glucose intake on postprandial glucose levels', Scientific Reports, 15(1), 22662. doi: 10.1038/s41598-025-07312-y.

Rosen, C.J. and Ingelfinger, J.R. (2026) 'GLP-1 receptor agonists', New England Journal of Medicine, 394(13), pp. 1313-1324. doi: 10.1056/NEJMra2500106.

West, S., Scragg, J., Aveyard, P., Oke, J.L., Willis, L., Haffner, S.J.P. et al. (2026) ‘Weight regain after cessation of medication for weight management: systematic review and meta-analysis’, BMJ, 392, e085304. doi: 10.1136/bmj-2025-085304