Thinking about Mounjaro or Wegovy?

The nutrition essentials you need alongside GLP-1 weight loss injections for results that last.

Here's what you need to know about GLP-1 weight loss injections.

Originally developed to support clients with diabetes, GLP-1injections are making headlines as a miracle weight loss drug.  They are without doubt shifting the landscape of obesity treatment, with clinical trials reporting reductions in bodyweight by between 5-18%. (Source)

Unless you’ve been hiding under a stone, you’ll have heard about them everywhere online -with some people raving about how they’ve changed their lives, others reporting exhaustion, nausea and bloating, and some warning that as soon as you stop, the weight piles back on

The reality? All of these things can be true.

These medications can help.  They can reduce hunger, improve blood sugar control and lead to weight loss.  But they are not a miracle cure.  And if you’re not careful, the cost isn’t just financial, it can affect your energy, digestion, mental health and even your results. 

So, if you’ve started taking one of these weight loss injections (or you’re thinking about it), I’ve written this blog for you.

We’ll explore:

• How this medication actually works

• Why side effects happen

• What your body needs to function properly while taking it

• How to avoid the most common mistakes (especially if you want lasting change)

** Please Note - This blog is for educational purposes. It’s not a substitute for personalised medical advice, nor does it replace guidance from your prescriber. Always consult your healthcare provider before making changes to medication, diet or lifestyle. My aim is to give you practical steps to help make your investment worthwhile. Building the right habits now will also support you when you’re ready to move away from medicated weight loss.

How do weight loss injections like Mounjaro and Wegovy work?

Glucagon-like peptide-1 (GLP-1) is a natural hormone your body releases after you eat. It slows stomach emptying, steadies blood sugar, and signals fullness to your brain. GLP-1 injections mimic the actions of this hormone, which is why they can dramatically reduce appetite and “quiet the food noise.”

Currently there are 2 medications licensed for use in weight loss and weight management in the UK.

Wegovy contains the ingredient semaglutide, and works by mimicking the action of GLP-1.

Mounjaro goes a step further. It contains tirzepatide, which mimics not only GLP-1 but also another natural hormone, called GIP (glucose-dependent insulinotropic polypeptide) that's involved in appetite and blood sugar control. This “dual action” can make appetite control stronger and may lead to even greater weight loss for some people.

What this means for your body:

• Less hunger - meals feel satisfying more quickly.

• Slower digestion - food stays in the stomach longer, leading to earlier feelings of fullness (but sometimes bloating or nausea if meals are large).

• Steadier blood sugar - fewer spikes and crashes, especially helpful if you have insulin resistance.

• Reduced inflammation - some people notice fewer aches and pains.

Here’s what can also happen…

• You eat far less, but not necessarily the right foods.

• Your energy drops because you’re under-fuelling.

• Your digestion slows, leading to symptoms like constipation, nausea, bloating and reflux.

• Your muscle mass starts to decline, making weight regain more likely.

What happens in tthe first weeks of Mounjaro or Wegovy?

The first weeks can feel strange. Your appetite drops. Food may even lose its appeal altogether. You might feel on top of the world - or you might feel rubbish. All of these reactions are normal.

What you eat becomes more important than ever, because your body still needs nutrients to function well. Choosing a well balanced nutrient dense diet is key to feeling good. Eating regularly, even when you aren't feeling hungry is also important. Skipping meals or eating tiny portions can increase nausea, and leave you feeling exhausted.

It's helpful to start a simple food and symptom log too - keeping a note of how you feel after each dose, what you eat, how your digestion responds and any other symptoms you notice.

Three nutrition non-negotiables (even when you’re not hungry)

1.     Hydration

Aim for at least 2L daily (water or herbal teas). Helps prevent nausea, constipation and headaches.

2.     Fibre to support digestion and blood sugar balance

Aim for 25–30g daily. But build up gradually to avoid bloating.

You'll find fibre in fruit, veg, beans, lentils, chickpeas, wholegrains.

Easy ways to add fibre: add chia or flaxseed to yoghurt, add lentils to soups, eat an extra veg with each meal, swap white bread for seeded wholegrain.

3.     Protein to protect your muscle and metabolism

Protein helps to preserve muscle while losing fat. and muscle is the key to keeping your metabolism active. It also enhances glucose sensitivity and burns more calories at rest.

Ideally aim for 1.2-1.6 g protein per kg body weight per day, and spread it across your meals.

Easy ways to add protein: Choose yoghurt with berries and seeds, protein smoothies, scrambled eggs on wholewheat toast, chicken or tuna salad with seeds, tofu stir fry.

Managing side effects of GLP-1 injections

It’s common to experience side effects along the way.  They are usually manageable with the right strategies. (Source)

Nausea & reflux

• Eat smaller meals more often (and don’t skip meals!)

• Try crackers, ginger or peppermint tea to help settle the stomach.

• Avoid lying down within two hours of eating.

Constipation

• Increase fibre gradually (eg oats, berries, chia seeds, cooked vegetables).

• Drink at least 2 litres of fluids daily.

• Gentle walks or stretching helps move food through the digestive tract.

• Eat magnesium-rich foods (nuts, seeds, leafy greens).

Food aversions

• When you don't feel hungry or your interest in food is low, protein smoothies, yogurts, soups and foods like cottage cheese can provide the nutrients you need ,and feel more appealing than foods like meat, hard cheesses and eggs

Low energy

• Ensure you are eating enough. Aim for three balanced meals, even if hunger is low.

• Prioritise protein and fibre at each meal.  Protein and slow-release carbs (quinoa, sweet potatoes, brown rice) to help stabilise energy.

Mood changes

• Sudden drops in food intake can affect your brain chemistry.

• Protein supports feel-good brain chemicals (such as serotonin and dopamine).

• Light outdoor activity boosts both energy and mood.

• Speak to your prescriber if low mood persists.

Feeling dizzy/lightheaded

• Often linked to dehydration, lowered blood pressure or rapid weight loss.

• Drink plenty of water and eat foods rich in potassium and magnesium (eg leafy greens, nuts, seeds, bananas, sweet potatoes).

• Monitor your blood pressure especially if you know yours is normally on the low side.

Do seek medical advice if you experience persistent vomiting, if you have severe abdominal pain, or if mood changes include anxiety or depression.

What happens when you stop taking GLP-1 weight loss injections?

If you haven’t used the time on the medication to build new healthy habits (maybe you just followed hunger cues or the lack of them), your chances of regaining the weight are high. (Source)

While some experts say certain people may need these medications long-term, many (especially those paying privately) want to transition off. (You will be guided when to do this by your prescriber)

Here’s what you need to know:

Appetite often returns strongly.

Weight regain is likely if you haven’t built healthy habits.

How to avoid weight regain:

• Build healthy habits now while your appetite is lower (balanced meals, regular movement, strength training).

• Don’t skip meals even when you’re not hungry. Regular eating keeps blood sugar stable and protects muscle.

• Work with a professional to create nutrition and lifestyle strategies that last.

Why nutrition and lifestyle support is key to lasting weight loss

Old habits can sneak back when medication stops if they haven’t been replaced with new routines. Without behavioural change coaching or nutritional support, research shows people can regain up to  75% of the weight lost (Source)

If you’re not also prepared to change your habits, you won’t get the best from your medication long term. This is why working with a qualified practitioner is a worthwhile investment alongside your treatment and gives you a far greater chance of lasting results.

Support can include:

• Nutrition tailored to your appetite and activity levels

• Practical strategies for side effects 

• Healthy habit formation to build satisfying meals, and long-term routines

• Mindset support to manage emotional eating and navigating hunger cues

• Planning for maintenance – so healthy eating feels sustainable whether youre on medication or not. 

Final word: combining GLP-1 weight loss injections with nutrition for results that last

Medication can be a helpful tool, but it’s not a cure. Combining GLP-1 therapy with good nutrition, movement, sleep and mindset support is the best way to get results that last.

I’d love to support you on your weight loss journey. Whether or not you choose GLP-1s, I can help you build the foundations for lasting change.

BOOK YOUR FREE 30-MINUTE NUTRITION STRATEGY CALL HERE