With so much media hype around the new weight loss injections like Wegovy (semaglutide) and Mounjaro (tirzepatide), and as I see more and more people in my diabetes prevention groups starting to take them, I thought it was time to look in more detail at how they work and whether they really are a miracle fix, or are there hidden risks?

The Promise
Originally developed for diabetes, these injections are administered via a weekly injection and belong to a class of drugs known as GLP-1 (glucagon-like-peptide-1) receptor agonists, which work by mimicking the hormones that regulate our appetite, normally released in response to food. Mounjaro also targets GIP (glucose-dependent insulinotropic polypeptide)receptors, making it potentially more effective for some people.

These drugs work by reducing your levels of hunger and increasing your feeling of fullness. They slow the rate at which food leaves the stomach and improve insulin sensitivity, which can lead to substantial weight loss when combined with lifestyle changes. On average, 90% of those using Wegovy lose 5% of bodyweight in 6 months and some studies show a 15-20% loss of body weight over 15 months. In clinical trials of Mounjaro people lose up to 15 to 25% of body weight in the first year, depending on dose.

Additional benefits include:

• Improved Blood Sugar Control – helping to regulate insulin and blood glucose levels, which can be beneficial for those with type 2 diabetes or metabolic syndrome.

• Potential Cardiovascular Benefits – studies suggest they may lower blood pressure and cholesterol, improving overall heart health.

• Reduced Cravings – By affecting hunger hormones, they help people eat less without extreme dieting.

The Risks

Despite their effectiveness, weight loss injections come with several potential downsides that should be carefully considered.

Common side effects include:

• Gastrointestinal Issues – including nausea, vomiting, diarrhoea, constipation, acid reflux and gallstones especially during the initial stages of treatment. These can be severe enough to impact daily life and many people give up after 2 months.

• Loss of Appetite – While appetite suppression is the goal, some users struggle to eat enough, leading to deficiencies in essential nutrients.

• Fatigue and Dizziness – Rapid weight loss and changes in metabolism may result in fatigue, dizziness, low energy levels, plus headaches and hair loss.

Long-Term Concerns

• Weight Regain After Stopping – Studies indicate that two thirds of people regain weight once they stop the medication if they have not made any lifestyle changes.

• Muscle Loss – Losing weight too quickly, especially without sufficient protein intake and exercise can lead to muscle loss rather than fat loss. A recent study showed that up to 40% of total weight lost was lean rather than fat mass.

• Cost and Accessibility - These medications can be expensive, and so not everyone will have access to them unless they’re prescribed on the NHS.

• Unknown Long-Term Effects - Since these are relatively new drugs, their long-term effects are unknown. Ongoing research is looking at potential links to thyroid tumours and pancreatitis.

The Vital Role of Nutrition in Sustainable Weight Loss

These medications are designed to help you lose weight WHILST making nutrition and lifestyle changes, not INSTEAD of. This ensures that once you stop taking them you’re less likely to regain the weight lost. Don’t also forget that we produce glucagon like peptide[GLP-1] naturally in response to eating, chewing, and digesting food.

The basics of good nutrition, with or without weight loss medication means:

• Focusing on Whole Foods – Processed foods contribute to inflammation and metabolic dysfunction. A diet rich in vegetables, fruits, proteins and healthy fats supports weight loss and overall wellbeing.

• Prioritising Protein Intake – Ensuring you are eating sufficient protein increases GLP1 and GIP secretion and helps you feel full, prevents muscle loss and keeps your metabolism active while losing weight. Think eggs, meat dairy and plant-based proteins.

• Supporting Gut Health – A healthy gut microbiome is vital for metabolism and appetite regulation. Eating soluble fibre delays stomach emptying and promotes the production of GLP1 in your gut, think oats, onions, bananas, garlic, leeks, yogurt and sauerkraut. Include probiotic fermented foods like yoghurt, kefir, sauerkraut and kimchi.

• Balancing Blood Sugar – Reducing refined carbohydrates and sugars and replacing them with complex carbs like quinoa and legumes helps stabilise blood sugar and energy levels.

• Not Avoiding Fat – Too many people still mistakenly think it is eating fat that makes them gain weight, however the more fat you eat, the more bile you produce and the more GLP1. Think extra virgin olive oil, nuts, seeds, avocados and oily fish.

• Staying Hydrated – Adequate hydration helps digestion, curbs cravings, and supports overall metabolic health, as well as positively influence GLP 1 and GIP secretion.

• Eating Regularly - Managing your eating pattern can help support GLP1 production and help you regulate your appetite. Avoid long periods of fasting if it increases the likelihood of overeating later.

• Avoid Over-eating - It desensitises your gut to GLP1.

Why Lifestyle Changes Also Matter

• Exercise is Essential – Strength training and aerobic activity help maintain muscle mass and improve metabolic health. Physical activity increases GLP1 and improves your body’s sensitivity to it.

• Mindful Eating – Slowing down and being conscious of portion sizes can help prevent overeating, even when hunger signals are altered by medication.

• Stress and Sleep – Chronic stress and poor sleep contribute to weight gain, which means that stress reduction techniques and good sleep hygiene are critical.

Final Thoughts

These new medications can be valuable tools for those struggling with obesity, but they are not a magic fix. They are designed to be prescribed to those who have obesity or weight-related health conditions, rather than as a quick fix for general weight loss. However, without addressing nutrition, lifestyle, and long-term habits, the benefits of these injections may be short-lived. A holistic approach that includes a nutrient-rich diet, exercise, and stress management is essential for sustainable, long-term lasting weight loss and overall health.