How to Eat Well on GLP-1 Weight Loss Drugs: A Nutritional Therapist's Guide to Long-Term Success

GLP-1 receptor agonists like Mounjaro (tirzepatide) and Ozempic (semaglutide) are revolutionising the weight loss landscape. With their ability to reduce appetite and help users shed significant weight, these drugs offer real hope for people who’ve struggled for years. But as a nutritional therapist working with clients on these medications, I’m seeing a more complex picture—one that calls for strategic nutrition support to avoid long-term harm.

In this article, I’ll explore the hidden risks of GLP-1 medications, practical dietary advice to protect your body, and how to use your time on these drugs to set yourself up for lasting success.

The Hidden Risks of GLP-1 Medications

GLP-1s don’t just suppress appetite—they often reduce total calorie and nutrient intake. This can lead to a cascade of issues, especially when used without professional support.

1. Muscle and Bone Loss

Research shows that up to 25–40% of weight lost while on GLP-1 drugs may come from lean tissue, including muscle and bone. This has serious consequences:

• A slower metabolic rate, making it easier to regain weight later

• Increased risk of bone fragility

• Potential increase in fat mass when the drug is stopped

2. Nutrient Deficiencies

Smaller portions often mean fewer nutrients:

• Protein intake typically drops too low

• Key nutrients like iron, vitamin B12, vitamin D, calcium, and magnesium may be under-consumed

3. Digestive and Gallbladder Issues

Common side effects include:

• Nausea and vomiting

• Constipation

• Gallstone formation, especially with rapid weight loss

4. Emotional Eating Still Matters

GLP-1s reduce hunger—but they don’t automatically address emotional eating. If you’re using food for comfort, stress, or escape, those patterns may persist (or return) when the drug is stopped.

5 Nutrition Strategies to Thrive on GLP-1 Medications

The best outcomes happen when you use the drug as a tool to help you eat better—not just less.

1. Prioritise Protein Every Day

Aim for at least 1.2g of protein per kg of body weight, or roughly 100g/day. This helps preserve muscle and supports metabolism.

Here’s what that can look like:

• 1 chicken breast (120g) = ~30g protein

• 2 eggs = ~12g

• 1 cup cooked lentils = ~18g

• 200g Greek yoghurt = ~20g

• 1 tin of tuna = ~26g

• 1 scoop whey protein = ~20–25g

Spread protein across meals and snacks to maximise absorption.

2. Focus on Nutrient-Dense, Fibre-Rich Foods

With a smaller appetite, every bite must count:

• Colourful vegetables

• Healthy fats (olive oil, nuts, seeds, oily fish)

• Whole grains (quinoa, brown rice, oats)

• Legumes and pulses

These support gut health, blood sugar balance, and long-term appetite regulation.

3. Incorporate Resistance and Weight-Bearing Exercise

Even 2–4 short sessions a week can help maintain muscle and bone density.

4. Consider Targeted Supplementation

Depending on your blood tests and symptoms, you may benefit from:

• Vitamin D

• Magnesium

• Iron

• Calcium

• B12

Seek professional guidance before supplementing.

5. Use This Time to Address Emotional Eating

With appetite quietened, you have space to explore your patterns around food. Journaling, therapy, and mindfulness can be transformative.

The Rebound Risk: What Happens When You Stop?

Studies show that most people regain the weight they’ve lost on GLP-1s if no behavioural or dietary changes are made during treatment. In some cases, fat mass increases beyond baseline due to lowered muscle and metabolic rate.

That’s why I work with clients to use their time on these medications wisely:

• Protect muscle with strategic protein intake and movement

• Build sustainable eating habits

• Address emotional relationships with food

Should You Work with a Nutritional Therapist?

If you’re on a GLP-1 drug or considering one, working with a nutritional therapist can:

• Reduce the risk of nutrient and muscle loss

• Help you feel stronger, more energised, and more confident in your body

• Improve long-term outcomes when you stop the drug

I regularly collaborate with GPs, pharmacists, and other healthcare professionals who want their patients to succeed beyond the prescription.

Final Thoughts

GLP-1 medications can absolutely be a game-changer—but they’re not a magic fix. Use them as a window of opportunity to build strength, nourishment, and confidence that will support you for years to come.

If you’d like professional support tailored to your journey with GLP-1 medication, I’d love to help.