Weight Loss Injections: A Nutritional Therapist’s Perspective

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Weight loss is a topic that often sparks interest, especially with the introduction of new medications generating widespread attention. For women over 40 and during menopause hormonal shifts and lifestyle changes can make managing weight even more challenging. While these medications offer promise, understanding their mechanisms, benefits and limitations is essential.

As a nutritional therapist, I believe it’s important to have a balanced view of these medications. They can be a helpful tool for some individuals, particularly when combined with a healthy lifestyle. However, they should not replace the foundational elements of good health, including nutrition, physical activity, stress management, and sleep. These lifestyle factors remain essential for sustainable long-term wellness.

How Do the New Weight Loss Medications Work?

Recent developments have focused on medications that target specific hormones to regulate appetite and metabolism. Here’s an overview of the most talked-about drugs:

GLP-1 Receptor Agonists (e.g., Semaglutide)

These drugs mimic the hormone GLP-1, which helps control appetite and food intake. By enhancing satiety (the feeling of fullness), they reduce calorie consumption and promote weight loss.

Commonly marketed as Wegovy or Ozempic (originally for type 2 diabetes), semaglutide has shown weight loss ranging from 15-20% of body weight when combined with a calorie-controlled diet and increased physical activity. Known as Wegovy in the US and Europe, and Ozempic for diabetes-related uses, the drug can lead to side effects such as nausea, diarrhoea and constipation. Rare but serious side effects include gallstones and pancreatitis.

Dual Agonists (e.g., Tirzepatide)

Tirzepatide activates both GLP-1 and GIP (glucose-dependent insulinotropic polypeptide) receptors. This dual mechanism helps regulate appetite and improve metabolic efficiency.

Sold as Mounjaro in the US, it has been reported to result in weight loss of up to 25% of body weight over a year. Side effects are similar to GLP-1 agonists, including nausea and diarrhoea, with additional risks such as depression or thyroid concerns. The drug is approved in the US and gaining traction in Europe.

Triple Agonists (e.g., Retatrutide)

These target three receptors: GLP-1, GIP, and glucagon. This multi-receptor activation aims to optimise appetite suppression, insulin sensitivity, and energy expenditure.

Early studies suggest significant weight loss potential, but long-term data is limited. Retatrutide is still in clinical trials in some regions, with availability expected to expand in the coming years.

Older Medications: Orlistat

Orlistat inhibits the absorption of dietary fat by blocking the enzyme lipase. Roughly 25-30% of fat intake is excreted rather than absorbed.

Orlistat leads to modest weight loss of 5-10% of body weight when combined with a low-fat diet. Common side effects include fatty stools, frequent bowel movements, and urgency to defecate, especially if dietary fat intake is not reduced. It is sold under the brand names Xenical (prescription) and Alli (over-the-counter) in Europe and the US.

Nutrition and a Healthy Lifestyle: The Foundation of Weight Loss

While these medications can support weight loss, they are not a replacement for a healthy lifestyle. Sustainable weight management relies on addressing the root causes of weight gain.

Nutrition: Focus on whole, nutrient-dense foods. A diet rich in fibre, protein and healthy fats can promote satiety and hormonal balance.
Physical Activity: Regular movement is critical for maintaining weight loss and improving overall health. A mix of strength training and cardio provides the best results.
Stress Management: Chronic stress can lead to hormonal imbalances that contribute to weight gain. Mindfulness practices, yoga, or deep breathing exercises can help.
Sleep: Poor sleep disrupts appetite-regulating hormones, increasing cravings for high-calorie foods.

The Need for Long-Term Research

These medications are relatively new, and while short-term results are promising, the long-term effects are still unknown. Some areas requiring further investigation include:

Sustainability: Studies show weight regain is common after stopping medications. For example, up to 2/3 of the weight lost on semaglutide can return post-treatment.
Health Implications: The impact of prolonged use on organ systems, especially the heart and pancreas, needs to be studied.
Accessibility: These treatments are costly and may not be widely available in all healthcare systems.

Key Takeaways

Weight loss medications such as Wegovy, Mounjaro and Retatrutide are tools, not solutions, for managing weight. They must be combined with healthy habits for lasting results. Always consult with a healthcare provider to discuss potential benefits and risks and determine the most appropriate approach for your individual health needs.

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References

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Garvey, W.T., et al. (2022). Two-Year Effects of Semaglutide in Adults with Overweight or Obesity: The STEP 5 Trial. Nature Medicine, 28(10), pp. 2083–2091. https://doi.org/10.1038/s41591-022-02026-4.
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