With nearly one-in-four people in Ireland living with obesity, there’s huge interest in weight-loss solutions that work. Drugs like Ozempic have proved a game changer, but for some the side effects are too tough to live with. Enter glucose monitoring apps.

Vomiting on yourself in the shower in the middle of the night isn’t much fun, and there’s something particularly grim about knowing it’s self-inflicted. But for people like me, who just can’t tolerate the side effects of the newest class of weight-loss drugs like Ozempic, Wegovy and Saxenda, this isn’t an unusual experience.

Semaglutide — the pharmaceutical name for Ozempic, and the other drugs in this family — were developed ostensibly to help combat type 2 diabetes, but have gained significant acclaim as weight-loss wonder drugs. They work on the hormonal system in the body and have a seemingly miraculous ability to regulate the appetite of users. In clinical trials, people have lost as much as 21pc of their body weight, with many ancillary health benefits such as cutting the risk of heart attacks and strokes.

For those prescribed them, able to afford the cost and to tolerate the side effects, it’s possible to lose excess weight without needing to exercise much willpower.

Users find they just don’t feel as hungry as they used to, eat less and so lose weight. I lost weight too, but mostly because I was so sick that the thought of eating anything at all was out of the question.

But it was the 4am shower that made me call time on Ozempic. It was the middle of the night and I just couldn’t get warm in bed. I was about seven weeks into taking the drug and while I had lost around two stone, the side effects that are meant to fade with time weren’t going anywhere.

I was regularly vomiting, experiencing gastric upset and, because semaglutide slows down the rate at which you absorb food, having “sulphur burps”, caused by food fermenting in my gut before I had a chance to digest it. Mostly, these were manageable by avoiding certain foods and using over-the-counter medication, but on the night in question, I found myself shivering uncontrollably in bed and unable to get warm.

I decided a hot shower might stop my teeth chattering but what followed was grim, and I found myself wondering what I was doing this for. My doctor initially encouraged me to hang in there, because most people find the side effects subside after a few weeks, leaving the therapeutic benefit to work as expected, but ultimately we agreed this wasn’t a good match for me.

I took the injection at the start of each week and for seven weeks rode a roller coaster of nausea, frequent vomiting and gastrointestinal issues. I got hit worst at the beginning of the week but the nausea would diminish by the weekend. I’d get a day or so of feeling OK, and then it was time to take it again. Eventually, I broke. “This isn’t worth it,” I thought.

"It’s thought that the percentage of people who can’t tolerate the current generation of weight-loss drugs is about 4.5pc."

This family of drugs is so successful that it’s quite easy to spot people who’ve taken it — those who have struggled with excess weight all their lives and then all of a sudden seem to have cracked the code.

But behind the success stories, there are also a lot of people like me who just can’t tolerate them. Stephen Fry was recently interviewed for a food-themed podcast, Ruthie’s Table 4, about his experience with the drug. While he initially lost weight, eventually he was also forced to stop.

“I tried Ozempic years ago,” he told the podcast. “I’m an early adopter of these things, I happened to be in America and my doctor said, ‘I think I can get you some.’ He tried me on it and the first week or so I was thinking, ‘This is astonishing. Not only do I not want to eat, I don’t even want alcohol of any kind. This is going to be brilliant.’

“And then I started feeling sick. And then sicker and sicker and sicker. And I was literally throwing up four or five times a day. And I thought, ‘I can’t do this.’”

Fry isn’t alone. The comedian Amy Schumer has written about trying Ozempic and having to stop because it made her so sick she was unable to play with her son. She also publicly criticised others for not discussing how severe the side effects can be. Likewise, Sharon Osbourne has spoken about losing nearly 30 pounds on an injectable “weight-loss drug” but similarly having to stop taking it because of nausea.

It’s thought that the percentage of people who can’t tolerate the current generation of weight-loss drugs is about 4.5pc. It’s not a big number but a small percentage of a large number is still a large number. And millions of people around the world are taking these medications. For those who get hit hard by side effects, the impact really is significant. In severe cases like mine, it means not being able to leave the house.

And there’s a bigger issue with this class of drugs — once you stop taking them, you’re highly likely to put the weight you’ve lost back on. In studies by Novo Nordisk, the company that makes Ozempic, on average people gain back two-thirds of the weight they’ve lost on the medication within a year of stopping taking it.

The main reason is that semaglutide, liraglutide and other drugs of this kind work by mimicking the actions of a natural hormone in the body known as GLP-1 (glucagon-like peptide-1). Yes, they curb the user’s appetite but they don’t create long-term behavioural change.

It’s the very lack of need for willpower they create that makes them so remarkable — people taking these medications just don’t feel like eating as much or as often as they usually do.

But when a user stops taking the drug, their appetite comes roaring back and, with it, all their pre-existing behaviours and attitudes to food.

To be clear, there are other medical reasons why a person might be prescribed semaglutide, liraglutide or tirzepatide, and all offer valuable medical benefits above and beyond weight loss. Studies have shown they can reduce the risk of heart attacks and stroke even among people who don’t have diabetes.

But if losing weight is a person’s main reason for taking them, then they’re faced with a dilemma: continue taking the medication indefinitely or deal with putting the weight back on after they stop.

There’s no doubt we’re at the start of a medical revolution with regards to tackling health issues created by excess weight.

"The makers of Limbo are adamant that it’s not a diet, and users are free to eat whatever they like while using it. However, very quickly, you start to realise the impact what you’re eating has on your body." Alex Meehan tries out the Limbo continuous glucose monitor. Picture: Gerry Mooney

But for some the solution isn’t here yet, at least not in injectable form. However, there are other ways to biohack your system to help you make better choices. One of them is the use of a continuous glucose monitor (CGM), a medical device that attaches to your body and gives you real-time information about the impact the food you eat has on your body.

There are many of these on the market but for the last month I’ve been testing Limbo, a subscription programme developed here in Ireland. This combines a CGM with an AI-powered smartphone app to do what semaglutide can’t — stimulate weight loss through lasting behavioural change.

The idea is simple. You attach a small sensor — about two-thirds the size of a matchbox — to the back of your arm or your abdomen. It has a tiny filament that sticks painlessly into you and sits just below the surface of the skin with a transmitter linked to an app on your phone. The sensor talks to your phone and displays a continuous scrolling line measuring blood glucose levels.

This line rises or falls throughout the day, based on what you eat and on other factors such as how stressed you are, whether you do exercise and so on. To achieve weight loss, the idea is that all you have to do is keep your ‘Limbo line’ sitting within certain parameters.

The app gives feedback on your daily efforts and uses AI to gently nudge you into better habits as time goes on.

Crucially, actual human beings also monitor your progress and check in to make sure that you’re heading towards your goals.

The makers of Limbo are adamant that it’s not a diet, and users are free to eat whatever they like while using it. However, very quickly, you start to realise the impact what you’re eating has on your body.

For people who want to lose weight, the idea is that you adjust your eating habits to encourage your body to burn its existing fat stores rather than prioritising the energy from the food you eat.

Some foods such as sugar, refined carbs and many processed foods act like petrol thrown on a fire. They burn fiercely and provide a dump of energy into your system, but eating them throws you out of ‘limbo’ because they stop you burning fat.

In addition, foods like these deliver energy in such large quantities that unless you’re burning off very large amounts through exercise, your body will try to store it. They add to your stored fat reserves instead of helping you lose excess weight.

They burn quickly, fade fast, leave you feeling bad, and you’re soon hungry again. Instead, Limbo heavily steers users towards what it describes as “carbconscious, protein-positive and nutrient-rich” foods. What this means in practice is avoiding carb-heavy foods like bread, pasta, rice and potatoes, and reducing processed and overtly sweet foods. Meals are built around proteinrich foods like meat, fish, eggs, non-starchy vegetables, and lots of full-fat dairy, nuts and seeds.

Diet and low-fat foods are discouraged, and it doesn’t take long before a ‘gamification factor’ sets in. Being able to see within minutes of eating or drinking something what impact it has on your blood is fascinating. Eat a chocolate bar or a plate of pasta and you will see your line ‘spike’ into the red zone.

Keep it in the green zone, minimise spikes and essentially you’re losing weight. In addition, it’s highly likely that you’ll feel better and have more energy than before. Paradoxically, not all spikes on your line are bad — those caused by food are to be avoided but spikes caused by exercise or by taking a cold shower are good, and accelerate weight loss by speeding up your metabolism.

Exercise is part of the system, but not in the way that you might think. Limbo recommends two types: the first is low-intensity steady-state (LISS) exercise, which means walking, cycling, gardening, cleaning and generally being active but not sprinting or pushing yourself overly. For example, the app recommends hacking your metabolism by going for a 20-minute walk after dinner each day. The idea is that this isn’t to burn fat but rather to train your metabolism on what to do with the energy it has just ingested, to use it rather than store it.

The second form of exercise recommended is high-intensity training (HIT), which is a lot tougher, and it recommends you do this early in the day before eating anything. The idea here is to create a surge of adrenaline that helps to spike your line and keep your body processing energy more efficiently throughout the day.

“The fact that this isn’t a diet is really important. You’re not given a bunch of rules or a plan to follow; instead you get constant coaching and little nudges based on what you eat. The point is to show you whether or not you have too much energy in your system,” says Liton Ali, a representative for Limbo.

“Blood glucose is a thing you can control and when you do so, you also control several hormones that impact your weight, appetite and satiety. They control things like whether or not you will have food cravings and whether your brain thinks it’s hungry.”

The goal of the system isn’t actually weight loss — that’s a side effect. The goal is to train the person’s metabolism, and it’s for this reason that the programme changes over time. “At the beginning in week one, you’re encouraged to reduce your carbohydrate intake intensively and if you manage to do that and flatten your line, you find that in week two that isn’t stressed quite so much. By week six, people can typically more than double the amount of carbohydrates they can eat in a week without sending your blood glucose up.

“That’s not something Limbo does; it’s just an ability our bodies have and the app just makes it visible and accessible,” Ali says.

So what happens if you follow the instructions? How much can you lose? Well, Limbo advertises that the average person who follows the programme drops 3- 5kg in a month, and will reduce their BMI by one to two points. In three to six months of use, they can lose as much as 10-20pc of their body weight, a figure comparable to that possible with Ozempic and other semaglutide-type medications.

Personally, I lost around 3kg in a month of using the system, but perhaps more interesting is the insight I gained into how my body processes food and, frankly, that I was eating more than I realised.

It’s hard to predict the future to see if this experience will prompt lasting change, but I can’t ‘unknow’ what I now know about what foods suit me and what foods have the potential to damage my health.

Limbo is an expensive programme to take part in — €295 for the first month for the hardware, AI app and coaching, and €130-195 for subsequent months depending on the length of time you sign up for — but, unlike Ozempic, which cost me around €160 per month, the idea isn’t that you stay on it indefinitely.

A month is the minimum time recommended but three months is optimum. While you might not lose all the weight you want to in that time, you will gain insights likely to stay with you for life.

Living with this kind of system is tough. Feedback from the app can be ruthless and for my first few days, it seriously disapproved of my choices, sending notifications such as “this food choice is not helping you towards your goals”. There’s zero room for negotiation and you can’t hide or lie to yourself about what you’re eating.

One interesting aspect of the Limbo experience is realising that there is sometimes a correlation between your mood and your blood sugar. We’re all aware of what happens when we allow ourselves to become ‘hangry’, when we let ourselves get over-hungry and our mood suffers, but that’s notable because it’s extreme.

Actually, even slight dips in blood glucose can make you feel a bit down, without you necessarily realising what’s causing it. I started to check the app when I felt off to see if there was a correlation, and there frequently was. An interesting extra benefit.

Continuous glucose monitors of the type that Limbo is built on aren’t new and have been around since the 1990s. They are used by millions of people with type 1 and 2 diabetes around the world to monitor their blood sugar levels and avoid hypo- and hyperglycaemia. But using a CGM to help with weight loss is a much newer idea, and one that isn’t yet backed by much high-level research. However, the idea of opening a data-driven window into the workings of your body is compelling.

"Using a CGM to help with weight loss is a much newer idea, and one that isn’t yet backed by much high-level research. However, the idea of opening a data-driven window into the workings of your body is compelling."

And there’s no doubt that obesity is a problem in Ireland. Nearly one-in-four people here is living with obesity, and as a problem it’s getting worse. In 1990, obesity rates were 8pc for men and 13pc for women in Ireland. Today, according to the Healthy Ireland Survey, around 60pc of adults in Ireland are overweight or obese, and as a country we have one of the highest levels of obesity in Europe.

Dr Sumi Dunne is a GP and lecturer at the Royal College of Surgeons in Ireland, who is keen to see the way we talk about obesity change. “What we know is that the ‘eat less, move more’ approach to managing weight loss just doesn’t work,” she says. “This is a multifactorial problem and we have to come at it from that perspective. Yes, there’s a scientific and medical perspective but there are also economic and behavioural issues to be considered.

“For example, societal influences like where you grew up, what kind of education you had and what your access to healthcare is like all have a huge impact on your health.

“Your genetic make-up, what medications you take, how well you sleep and handle stress, what your job is — all these play a big role in how easy or hard it is to lose excess weight. Shift patterns and disruptions to sleep cycles, for example, are notorious for playing havoc with people’s metabolisms.”

Dunne sees patients all the time seeking to manage their weight and has generally found people respond well to Ozempic and Saxenda. But she thinks that creating lasting change for people managing their weight requires a rethink in how we relate to the problem. “There’s so much to it that the reductionist approach of saying ‘eat less, move more’ really isn’t helpful. We need to get rid of that so when we as doctors are supporting our patients who are overweight or obese, we approach it as we would any other chronic disease — helping to identify all the factors they need to manage to optimise their journey. Because that’s how we look at every other chronic disease, so why look at this one differently?”

Demand for GLP-1 medications like Ozempic, Saxenda and Wegovy is only going in one direction, as more and more people look for new ways to manage their body weight more effectively. It’s likely that new medications will appear that refine the experience of taking these drugs, and reduce side effects. Semaglutide in pill form — rather than as an injection — is already available and Novo Nordisk, the maker of Ozempic, is also trialling a next-generation medication called amycretin that appears to be more effective in early trials than previous weight-loss drugs.

In a phase-one trial, it said the drug reduced the body weight of test subjects by 13pc in three months, compared to 6pc in the same period for semaglutide, although these test results haven’t yet been published in a peer-reviewed journal.

Novo Nordisk’s patent for Saxenda, made with liraglutide, has recently expired and it’s highly likely that generic versions from the likes of Pfizer and Mylan will help take the price down and improve availability of these medications.

But as with everything in our lives, tech is also likely to play a bigger role. It’s believed that Apple is actively trying to develop a non-invasive blood-glucose monitor function for its smartwatches that won’t need to use a needle or filament to puncture the skin. The business news website Bloomberg has reported that the technology already exists, but is still too big to fit on a person’s wrist. However, it’s likely that a smartwatch that can report on your blood glucose isn’t that far away.

From my own experience, a system such as Limbo is expensive but it does work. I don’t know if I’d continue to use it indefinitely, but I’ve definitely learned from it. For instance, I always knew that carbs weren’t great for me, but I didn’t realise just how counterproductive to my health they were. As a middleaged person with a slowing metabolism, I will never make them a core part of my diet again.

Professor Donal O’Shea, the HSE’s national clinical lead for obesity, was quoted at the Irish Medical Organisation’s conference earlier this year saying that “obesity is going to be a historical phenomenon” and that young medical students training today will likely not see obese patients in the future.

“Ozempic will be old hat in a couple of years’ time because what’s coming is way better, way more effective,” he said.

The future of those drugs and related technologies will likely be enormous. In five years, or maybe 10, will obesity as a medical issue in our society exist — and will the likelihood of you reading articles like this be practically zero