AFTER 10 years of trying every diet going, mum Lynsey Macfayden was among the millions of Brits who decided to try Mounjaro in a “last-ditch” attempt to shift the pounds.
And while the 33-year-old lost an impressive 10 stone, common side effects left her feeling drained.
But, eight months into her Mounjaro journey, the mum-of-two had a realisation that changed everything.
Lynsey tried everything from restrictive diets to Weight Watchers and Slimming World before going on in November 2024.
When she started using the fat jab, she thought the key to her success would be eating less, as the drug lowers appetite.
And initially, this technique seemed to work. She lost 5st 7lbs in just eight months, going from almost 21st 5lb to 15st 12lb.
But once eight months had passed, Lynsey realised she had been making a big mistake. And it was a mistake she wished she’d realised far sooner.
While she was eating less, she wasn’t necessarily eating better, and it was making her feel unwell.
Before starting Mounjaro, Lynsey’s diet consisted mostly of convenience – takeaways, instant noodles and .
Once on the fat jabs, this didn’t change. While she was now eating smaller quantities of these foods, she still wasn’t eating a balanced, or nutritious, diet.
This is a trap that many jab users fall into and in some cases, it risks leaving people malnourished.
Rob Hobson, a registered nutritionist and author of Unprocess Your Life , calls this the “GLP-1 nutrition trap”.
This is when people “[assume] that because you’re successfully eating less and losing weight, you must be eating well”, he says. But this isn’t the case.
“A much smaller appetite creates a new nutritional challenge; your appetite may have fallen, but your body still needs to be nourished,” he says.
“If you’re suddenly eating half the amount of food you once did, you have fewer opportunities across the day to get , fibre, calcium, iron, essential fats and the range of and minerals your body needs.
“That’s why I tell people that when you’re eating less, every mouthful needs to work harder.”
Rob continues: “This doesn’t mean every meal has to be nutritionally perfect or that you have to fill your cupboards with specialist products or expensive foods.
“It simply means thinking a little more carefully about what you put on your plate.”
In Lynsey’s case, she only realised she was making a mistake with her diet when she began to feel constantly , weak and dizzy.
Speaking about her journey with Mounjaro, the content creator, from , says: “My mindset was simply, ‘eat less’.”
After months of this, however, she realised that although she was losing weight, she “wasn’t necessarily giving [her] body the nutrition it needed”.
“During those first eight months, I was largely eating the same foods I’d always eaten, just in smaller portions,” Lynsey says.
“Despite losing a significant amount of weight, I was constantly tired and didn’t really feel any healthier.
“The major positive was eventually regaining my ability to walk, but otherwise I wasn’t experiencing the improvements I’d hoped for.
“If you rely entirely on to eat less, without learning new habits, maintaining your weight loss could become much harder [if you stop treatment or reduce your dose].
“I like to think of Mounjaro as stabilisers on a bike. It’s giving me the opportunity to learn how to eat in a way that works for my body.
“Learning about volume eating has been particularly useful. As hunger increases, I know how to build satisfying meals with larger portions of nutritious, while staying within my calorie goals.
“I want the habits I’ve developed to support me long after my weight-loss journey.”
Speaking about her adjusted diet, Lynsey adds: “The first thing I focused on was protein . I calculated my daily requirements and began aiming to meet or exceed them most days.
“From there, I started learning about fibre and researching ingredients that might support my general wellbeing and help me manage symptoms associated with my chronic conditions.”
The mum has , a condition where the brain has issues receiving and sending information to the rest of the body.
It occurs when brain networks controlling movement, sensation, speech, or awareness stop working properly, even though the structure of the brain is normal.
Symptoms include weakness in the arms or legs, functional seizures, tremors, facial spasms, and difficulties with speech and swallowing.
Continuing to speak about her journey, Lynsey says: “It became less about simply eating fewer calories and more about what I could add to my diet to support my body, in easy ways without adding excess bulk, as I am on a volume-restricted diet with GLP-1.
“For example, an easy switch was SuperNutrio high protein, high calcium milk.”
SuperNutrio (£2.25) has double the protein (70g per litre) than standard milk and, while protein may seem like a bit of a buzzword for a healthy diet, particularly in relation to GLP-1 medications, Rob says this is for good reason.
He explains: “When we lose a substantial amount of weight, we don’t lose exclusively body fat, as some lean tissue is usually lost as well.
“That isn’t unique to , [it] can happen with weight loss however it is achieved, particularly when weight loss is rapid or the calorie deficit is very large.
“This makes preserving muscle an important part of the conversation. Protein provides the building blocks our muscles need, so including a at each meal is a sensible place to start.”
Rob warns, however, that protein isn’t the be all and end all.
“One thing I worry about with the current conversation around GLP-1 nutrition is that people can become so focused on hitting a protein target that everything else gets pushed aside.
Small Appetite? Make Every Bite Count
When your appetite is small, focus on getting more nutrition from what you can manage by fortifying meals, adding nutrient-dense foods and making simple swaps, says Rob Hobson.
• Keep a few ‘Nourishing Dozen’ staples handy – eggs, tinned fish, yoghurt, oats, beans and lentils, nut butters and seeds are easy ways to pack more nutrition into smaller meals.
• Choose fortified foods – breakfast cereals can provide useful amounts of iron and B vitamins, while fortified plant milks can provide nutrients including calcium, B12 and iodine.
• Look at the milk you use – milk provides protein and calcium, and higher protein and calcium options such as SuperNutrio are a great option when appetite is small and you need to make every mouthful count.
• Try clear whey in a protein milkshake if a large meal feels too filling – clear whey is a low calorie, fast-absorbing protein
• Add rather than enlarge – a spoonful of seeds or nut butter, some Greek yoghurt or grated cheese can boost nutrition without making a meal substantially bigger.
Could eating too little leave you exhausted?
Feeling tired while taking a GLP-1 medication shouldn’t automatically be blamed on a particular nutrient deficiency, and symptoms such as persistent weakness or dizziness should always be discussed with your GP, says Rob.
However, if your appetite is so low that you’re consistently eating very little, it’s worth considering whether you’re actually getting enough energy and nutrition. This was the turning point for Lynsey.
“I wish I’d learnt the basics of nutrition from day one,” she says. “I was under-eating for the first six to eight months, and although I lost weight quickly, I don’t think I was fuelling my body properly.”
Her experience is also a useful reminder that the aim shouldn’t simply be to eat as little as possible because the medication makes that possible.
Weight loss is only one part of health. The better question is: how can I use this smaller appetite to build a way of eating that still nourishes my body?
For Lynsey, that meant gradually changing the quality of her diet, prioritising protein, calcium and fibre, and eventually, introducing strength training.
“Losing weight is amazing,” she says. “But feeling strong again is even better.”
And that, for me, is the bigger nutrition message around GLP-1 medications. It’s not just about eating less but learning how to make what you do eat count.
“You still need fibre, which can help with some of the more common side-effects such as or other health issues like .
“Fruit and vegetables are still important, as are healthy fats and wholegrain carbohydrate foods. Together these foods will also supply you with a broad spectrum of ”
Once Lynsey realised her diet mistake and shifted her approach to eating, she says she “noticed a real difference in [her] overall wellbeing”.
“One of the biggest changes I’ve noticed is how quickly I recover from flare-ups of FND,” she says.
“Previously, a flare-up could take me weeks to recover from. Now, I often find I’m recovering within days. I’ve also noticed I seem to pick up everyday illnesses, like , less frequently.
“I’m also now able to strength train when my FND allows, which has been a massive game changer.
“Building strength to better support my unstable joints is incredibly important to me.”
After 18 months on , Lynsey has lost 10st 4lb and dropped 12 dress sizes. She now weighs 11st 1lb.
Lynsey is incredibly proud of how far she’s come, saying: “I’ve stuck with the journey, learned an incredible amount about nutrition and reached a point where I genuinely feel confident in my food choices.”
She stresses that Mounjaro hasn’t just allowed her to lose weight, it’s also enabled her to make healthier choices.
The mum adds: “I’ve learned a lot about how I want my life to look after weight loss.
“I don’t just want to be smaller; I want to be stronger, healthier and more independent.”
