Jump to: Understanding Mounjaro’s impact on appetite | Best protein-rich options | Managing side effects through food choices | What to order | FAQs | Take home message
Generally, we don’t recommend eating at McDonald’s regularly if you’re taking Mounjaro, aiming to lose weight, or wanting to improve your health.
Regularly eating fast food like McDonald’s is ultra-processed and can lead to poor health outcomes and increase the rate and severity of side effects linked to Mounjaro, like nausea, vomiting, and diarrhoea.
However, you can make more mindful decisions if you choose to go. We recommend choosing protein-rich options at McDonald’s and eating slowly to lower the risk of experiencing side effects.
McDonald’s can create challenges for Mounjaro users because the medication slows digestion, and ultra-processed foods can exacerbate GI-related side effects.
Many of us worry about making the ‘wrong’ choice and disrupting our progress, but occasional visits won’t harm our health if we’re eating a diet based on whole foods the majority of the time.
One of Mounjaro’s most significant benefits is how it quietens ‘food noise’, those constant thoughts about food and cravings that can drive poor choices.
This may make McDonald’s visits easier to navigate as we won’t be as likely to overeat.
Understanding Mounjaro’s impact on appetite and food choices
Mounjaro works by mimicking hormones that regulate hunger and fullness, fundamentally altering how your body responds to food.
The medication reduces appetite and hunger, helping you eat fewer calories almost immediately after starting treatment.
Mounjaro also slows gastric emptying, meaning food stays in your stomach longer. This creates a prolonged feeling of fullness but can make high-fat, ultra-processed foods particularly uncomfortable, and may worsen side effects such as nausea and bloating.
One of the most significant changes people notice is the reduction in ‘food noise’ – those constant thoughts about food and cravings that previously drove food choices.
This mental clarity makes it easier to make more mindful choices, such as choosing a healthier option at places like McDonald’s, rather than being driven by cravings for ultra-processed foods.
Our taste preferences often change on Mounjaro. Many people report losing interest in fried and heavily processed foods, finding them too heavy or unappetising. This shift helps guide you towards better choices when you do visit McDonald’s.
Best protein-rich options
When taking Mounjaro, maintaining muscle mass becomes important as lower hunger can lead to inadequate protein intake.
We recommend ensuring each meal contains a protein portion at least the size of an open hand, with protein-rich snacks between main meals if needed.
The Quarter Pounder with Cheese provides 30g of protein and feels more substantial. The McCrispy Deluxe delivers 27g of protein, though the fried coating might be harder to tolerate if you’re experiencing nausea.
For breakfast, the Egg McMuffin stands out with 17g of protein.
The Sausage McMuffin with Egg provides more protein (20g) but also contains more refined fat, which may trigger discomfort.
Budget-friendly options include the McDouble, which contains 22g of protein. Six-piece Chicken McNuggets offer 14g of protein in a smaller portion.
Managing side effects through food choices
Over 65% of people taking Mounjaro experience some gastrointestinal side effects, particularly nausea and constipation.
Ultra-processed foods are the primary trigger for nausea in GLP-1 users. McDonald’s fried items can overwhelm your slowed digestive system. Many people find that foods they previously enjoyed become difficult to tolerate.
Fast food like McDonald’s is often eaten quicker. Fast food is engineered to encourage faster eating, which can lead to increased consumption.
So, we recommend eating fast food, like McDonald’s, slowly to help avoid the GI side effects linked to Mounjaro.
Nearly half of Mounjaro users experience constipation, making fibre intake important.
Unfortunately, McDonald’s removed salads from its UK menu, limiting the availability of fibre-rich foods.
Most menu items contain only 2-3g fibre, with small chips offering the highest at 3g per serving.
McDonald’s menu fundamentally lacks vegetables, which means it doesn’t align with the balanced plate approach we recommend for optimal health and weight loss: 50% vegetables, 25% protein, and 25% complex carbohydrates.
This imbalance is why McDonald’s should remain an occasional choice rather than a regular part of your eating pattern.
What to order
For breakfast, an Egg McMuffin with apple slices and black coffee provides a good source of protein and some fibre. This combination usually sits well if your digestion is sensitive to the medication.
When your appetite is very small, try six-piece McNuggets with apple slices and water. This gives you protein without too much food.
If you order a larger meal, a Quarter Pounder with cheese, apple slices, and water provides a high amount of protein.
Always drink plenty of water, as Mounjaro can reduce your thirst as well as your appetite.
McDonald’s free refills on water and sugar-free drinks are helpful when you need adequate hydration but don’t feel like drinking much.
Building sustainable habits beyond McDonald’s
Mounjaro isn’t a magic pill that allows you to eat ultra-processed foods without any impact on our health.
The medication works best when you’re actively building healthier habits that will support long-term weight loss.
McDonald’s falls into the category of ultra-processed foods that we recommend limiting whilst on Mounjaro.
These foods include fast food, microwave meals, most supermarket sandwiches, and heavily processed items that can worsen side effects and don’t support your health goals.
The core focus of using Mounjaro successfully is to calm down food noise, lower your cravings, and use this time to build healthier habits.
Occasional McDonald’s visits won’t derail this process, but they shouldn’t become a regular part of your new eating pattern.
Use the mental space that reduced food cravings provide to focus on learning to prepare simple, nutritious meals at home.
This is where the real, lasting change happens, not in perfectly navigating every fast-food visit.
Frequently asked questions
Will eating McDonald’s stop Mounjaro from working?
No, occasional McDonald’s visits won’t interfere with Mounjaro’s effectiveness. The medication works by affecting hormones in your gut and brain, not by analysing what you eat.
However, consistently eating ultra-processed and fast foods makes it more challenging to create the calorie deficit necessary for weight loss.
What’s the best McDonald’s breakfast for someone on Mounjaro?
The Egg McMuffin is a high-protein option at 17g of protein. Pair it with apple slices for additional fibre if you can manage it.
Why do I feel nauseous after eating McDonald’s on Mounjaro?
Ultra-processed foods like McDonald’s can trigger nausea because they’re energy-dense and fast-digesting, which can overwhelm your slowed digestive system.
These foods are designed to be hyperpalatable with refined ingredients that don’t work well with Mounjaro’s effects on your stomach.
Choose whole food options and eat smaller portions to minimise this.
Can I eat McDonald’s chips whilst taking Mounjaro?
You can, but many people find them difficult to tolerate due to the rate at which they’re digested, which may cause nausea.
If you want to try them, order a small portion and eat them slowly.
How much should I eat at McDonald’s if I’m on Mounjaro?
Listen to your body. When you feel comfortably full, stop eating.
Take home message
Eating at McDonald’s occasionally won’t harm your weight loss progress on Mounjaro.
When you do visit, focus on protein-rich options and listen to your body’s hunger and fullness signals rather than worrying about making perfect choices.
The real benefit of Mounjaro is how it quietens food noise and cravings, giving you the headspace to build healthier long-term habits.
Use this clarity to focus on developing a sustainable eating pattern based on whole foods, with plenty of vegetables, high-quality proteins, and complex carbohydrates.
Mounjaro works best when combined with sustainable lifestyle changes. The medication can help silence food-related thoughts and give you time to understand why your body may have struggled to lose weight before.
McDonald’s visits are part of real life, but we wouldn’t recommend visiting regularly if you’re aiming to lose weight and improve your health for the long term.
The most important thing is not to stress about occasional fast food visits. When life happens and you end up at McDonald’s, make choices that feel right for you at the time.
Second Nature’s medication programme
Second Nature provides Mounjaro as part of our Mounjaro weight-loss programme.
Why should you choose Second Nature over other providers assuming you’re eligible?
For peace of mind.
Second Nature has worked with the NHS for over 6 years, providing weight-loss programmes across the UK.
While our Mounjaro weight-loss programme is private and not currently used by the NHS, we’ve built the programmes focusing on scientific evidence, patient safety, and data security.
We hope that our 6+ years of working with the NHS and building a track record of effective weight-loss results will give you peace of mind to give us a try.
