Just how damaging is that afternoon snack or glass of wine? I used a glucose monitor to find out.
I am not diabetic. Nor am I prediabetic. I do however have a sugar problem. I start my day with croissants; chocolate, almond, even plain if there's raspberry jam to go with it. I've long suspected that my diet habits at work have me on a glucose roller coaster. My job as a writer is conducive to a lot of sitting and snacking.
However, I'm not overweight – around my work days I pack in yoga, tennis, rock climbing and dance classes. My mindset has always been: if I want your portion of cake as well as my own, I'll have it and work it off later.
My cavalier attitude towards sugar is not unique. There are more than 4.9 million people currently living with diabetes in the UK, 90 per cent of those with Type 2.
How many of us, who outwardly look pretty fit, are telling ourselves that we're managing just fine with the poor choices we're making day in and day out? And what effect is this having? The more glucose spikes, caused by eating sugar, we experience, the more insulin is released in our bodies. In the long term, chronically elevated levels of insulin bring problems of their own. Too much insulin is the root cause of obesity and Type 2 diabetes.
When I recently interviewed former UK Labour deputy leader Tom Watson, who reversed his diabetes, he suggested everyone with prediabetes should be prescribed a continuous glucose monitor (CGM) on the National Health Service.
Biohacking
You may have already seen some people wearing one. For the extreme health conscious, these continuous glucose monitors – small plastic discs worn on your upper arm – have become a tool to biohack their optimum diet and physical activities.
The epidemiologist and nutrition expert Prof Tim Spector started wearing one for research purposes five years ago, when he started working on Project Zoe, the world's largest in-depth nutritional research programme, in collaboration with scientists from Massachusetts General Hospital, King's College London, Stanford Medicine, and Harvard T H Chan School of Public Health.
"The first two or three times I used it were amazing," says Spector. "You get most of the insights at the beginning. Even a small glass of orange juice was giving me the same spike as a can of Coca Cola and I think when you see that for yourself it's very important."
He now wears one once every four to six weeks and finds it interesting when he travels to other countries, such as Japan, to see what impact the local food has on him. Long-term use has made him change what he has for breakfast and lunch. "Everything I ate looked healthy but was giving me a diabetic-level spike."
I'm a long way from developing insulin resistance, which is when the cells cannot absorb glucose, and levels build up in the blood. I do suffer from periods of lethargy and at times extreme exhaustion. This I've usually explained to myself is the result of too much physical activity. But could my diet be the real problem?
For two weeks I decided to join the CGM gang and the proof will be in the readings from my puddings. At the moment these monitors are available only to those with diabetes or if you're taking part in a research project, such as Project Zoe. For anyone interested in trying one, there are companies rolling out commercial offerings in the next six months.
American health company Abbott produces the FreeStyle monitor for Supersapiens, an Atlanta-based sports technology company focused on energy management systems to support sustained peak performance, and it is available in the UK. There's also NutriSense and Rockley Photonics, who are working with Apple on a non-invasive CGM for the Apple Watch.
In Glasgow, software developer Laura Douglas has designed the app MyLevels, currently in pre-trials, which helps users to interpret data collected from Dexcom sensors. Douglas first wore a monitor in 2018 after becoming interested in the subject. Her big personal takeaway? Steer clear of potatoes. She is excited about the possibility of how glucose regulation can support people trying to lose weight.
Glucose and fat
The simple science is that when blood sugar (or glucose) is high, the pancreas is triggered to produce more insulin to move that sugar out of your blood and into your cells. This is a problem for weight loss, because your body only burns fat when it senses insulin levels dropping. Once insulin has stored all the glucose it can in our liver and muscles, any excess glucose is turned into fat and stored in our fat reserves.
One of the most important things that happens when we flatten our glucose curves is that we automatically flatten our insulin curves as well. Understanding how you are spiking your blood sugars and learning to flatten those curves could be the key to more effective weight management. It's an exciting and appealing idea that focuses on types of food and when you eat them, rather than traditional diets that encourage calorie restriction.
The experiment
I ordered a FreeStyle LibreLink monitor, which is strictly intended for diabetes sufferers but is available online in the UK at £50 for a two-week monitor. While you don't need a prescription to purchase it, you do have to click the box saying you are diabetic to qualify. Abbott would prefer you didn't do so if you aren't.
The small disc is secured to the arm with a needle. Despite appearances, it was painless to attach by using an applicator and withstands showers and vigorous exercise. The app is rudimentary, recording data and allowing you to log comments on readings, but not interpreting them. This is why Spector currently thinks it's unsuitable for a lay person to use without the help of a registered dietician, a doctor or as part of a programme, because it is hard to interpret the data meaningfully.
It's something that Douglas hopes to address with MyLevels, which will include suggestions about altering your diet, or how to experiment with different results by taking a cold shower or going for a walk to see how it affects your spikes.
For my experiment I'm not going to change a thing about my usual eating habits. So on Monday morning, I buy my usual chocolate croissant at the station; 40 minutes later my reading has shot up from 5.4mmol/L (millimoles per litre) to 7.2mmol/L. I reassure myself that according to diabetes.co.uk, up to 7.8mmol/L is normal two hours after eating. However, my daily graph unfolds like a polygraph test: reaching as high as 7.9mmol/L after I'd had dinner.
I wonder what the cumulative effect of my day's food intake has been: the banana and apple from the employee fruit stand in the morning; the small squares of artisan chocolate, courtesy of the lifestyle desk's resident chocosseur; the M&S wrap followed by a lemon curd yoghurt, which I eat at my desk, and the 3pm furtive rendezvous with the office vending machine for a Cadbury Snack Bar.
Living at the sharp end
A daily pattern quickly emerges. By 6pm, at my desk, I'm at a 7.9mmol/L high. Leaving the office and walking for 35 minutes reduces it to around 3.9mmol/L. When I wake it hovers between 4 and 6mmol/L. For context, diabetes.co.uk states that a baseline concentration (also known as your fasting level, that is, your glucose level first thing in the morning before eating) between 3.9 and 5.4mmol/L is "normal"; between 5.5 and 6.9 mmol/L indicates prediabetes; and anything above 7.0mmol/L indicates diabetes.
Your glucose levels shouldn't increase above 7.9 mmol/L after eating. This is what's considered "normal", not optimal. I reach it multiple times. Quickly, I realise walking flattens this. My readings are also more stable on the day I use my standing desk for a few hours.
But there are more confusing readings. Yoga in my lunch hour three times a week appears to do little to stabilise my blood sugars.
On the second day, I receive the highest reading I had all fortnight after eating a third of a banana on an empty stomach while at the bouldering gym; 9.2mmol/L. For the rest of the two weeks I approach bananas with caution. There are the mornings I wake up to red readings 3.7mmol/L – inexplicable hypoglycemic (low blood sugar level) events in the night.
Easier to interpret is the 8.3mmol/L after a caramel bar enjoyed from my office chair at 3pm with a cup of tea. The half a can of fizzy rhubarb I chug back in the car after a hot day climbing on Dartmoor charts at 8.1mmol/L. I start to see how the way I start my day affects my cravings later in the afternoon. I wonder if the general brain fog I feel towards the end of the day is less tiredness than being dosed up on sugar.
If the Monday to Friday grind is more aptly illustrated by Hokusai's Great Wave, then by contrast my weekends are clear, calm pools of healthy choices and gentle, regular movement. The main difference? A later, more healthy breakfast of eggs or yoghurt with less sugar, and no long periods of sitting down.
My most stable day by far is a Saturday spent at a vegan friend's 40th birthday party lunch, where we feast on dishes of smoky sun-dried tomato hummus, and beetroot and pomegranate muhammara. I don't tip over 6.7mmol/L all day. However, it is the addition of half a bottle of champagne to wash it down that leaves me hopeful I've hit upon the elixir of glucose flattening.
Two weeks pass and I have many questions and a few hunches, namely that cereal, even the healthy-looking kind, is not doing me any favours when it comes to my glucose levels. Every weekday breakfast causes a surge. Bananas are powerful and to be approached with respect. Posh fizzy drinks are not to be consumed in isolation; consumed with a meal their effects seem less marked. Work, it is clear, is very bad for my glucose levels, but handing in my notice isn't a viable solution right now.
The Glucose guru
I contact the Glucose Goddess, aka Jesse Inchauspe, a scientist-turned-influencer with a passion for self-experimentation when it comes to glucose. She is enthusiastic about the utility of monitoring glucose levels for the 90 per cent of the population, who, even if they are not diabetic and are a visibly healthy weight, have glucose spikes every day.
"As I've discovered more about glucose, I've learned that there is a wide array of unwelcome short-term symptoms associated with spikes and dips, and they vary from person to person," she says. "For some, they're dizziness, nausea, heart palpitations, sweats, food cravings and stress; for others, like me, they're exhaustion and brain fog."
Inchauspe's community of glucose hackers – 870k followers on Instagram – don't necessarily wear monitors. They opt instead to make small lifestyle changes, such as the order in which they eat the food on their dinner plate ("eating veges first and carbs second greatly slows down the speed at which glucose makes it to the bloodstream, thereby flattening the glucose spike associated with that meal"), taking vinegar before a meal (apple cider vinegar in some water, with a meal, helps reduce the glucose spike of the meal) and then observing the effects.
Overall my average of 5.7mmol/L was in the normal range. However she immediately recognises two common habits from my logbook: a sweet breakfast and booze.
Start the day right
Eating cereal for breakfast, which I often do for cost-effectiveness and convenience during the week, is creating a big glucose spike, which then influences my glucose levels and cravings for the rest of the day.
"Starting with a savoury breakfast will change your day completely. Because our breakfast controls the rest of our day, even if you eat the same lunch and the same dinner, the spike of your breakfast will influence the spike of your lunch and dinner."
Inchauspe cites countries like Japan, where salad is often on the breakfast menu, and in Turkey you'll find meat, veges and cheese. "This hack is so powerful that if you go savoury for breakfast, you'll be able to eat sweets later in the day with few side effects."
That brings her to my afternoon slump. "Getting something from a vending machine that has sugar in it might make you feel you're getting energy, but actually what's happening is you're releasing dopamine in your brain. So it gives you pleasure, but it doesn't actually give you energy.
"When we eat something sweet, which creates a glucose spike, the energy from the food we just ate actually gets ushered away into storage, instead of being available for your body to use as fuel."
The best time to eat something sweet, says Inchauspe, is after you've already eaten a meal with fat, protein and fibre. "When we eat sugar on an empty stomach, we're throwing our system into a postprandial spin, riding on a big glucose and fructose spike."
Inchauspe advocates picking dessert over a sweet snack. If you like a mid-afternoon tea and biscuit you might be better off satisfying your cravings after your evening meal. So it seems I can still have my cake and eat it, just after a meal. The same is not true, it turns out, for alcohol.
The alcohol trap
"When people wear a glucose monitor they often find that when they drink alcohol their glucose levels stay steady," says Inchauspe. "They might interpret that as meaning that alcohol has no effect on their glucose levels, so it's okay to have it."
I certainly did.
"However, when we drink alcohol we are actually overwhelming our liver and that's the place from where new glucose is released into the bloodstream by your body. So when we drink alcohol we prevent our liver from releasing extra glucose into the bloodstream. So you might see a flat glucose curve or a decrease, but it's not truly a good flat curve or good decrease. It's down to essentially your body having to deal with a poison. So that's an interpretation we have to be mindful of," says Inchauspe.
The red alert drops to low glucose moments, though, are more likely a trick of the monitor, she says. "I wouldn't worry. The device can read low at night and it happens to me a lot," says Inchauspé. "Unless you have specific symptoms of hypoglycemia, like waking up in the night with a racing heart or night sweats, I would say this is a reading error."
She agrees about the power of walking to flatten curves. Members of her community have lost weight not by changing their diet, but simply by walking after a meal. A large 2018 research review looked at 135 people with Type 2 diabetes and found that aerobic exercise (walking) after eating decreased their glucose spike by between 3 and 27 per cent.
Working it out
But what of those fierce spikes during exercise? Thankfully they are not a problem either. "Exercise is the one case in which a glucose spike is okay," she says. "The reason we see a glucose spike is because the body is releasing glucose into the body to fuel our muscles, so they have the energy to contract."
So even though exercise does cause a glucose spike, and this can have side effects such as inflammation and ageing, in the balance, the benefits of exercise outweigh the damage of the spikes. There are some easy-to-understand hacks that I can start to incorporate into my daily routine. I don't have to give up my sweet things entirely, but having them at the end of a meal will help to reduce their effect.
I understand because of the monitor that I react quite strongly to bananas – but you might be different. One thing we all have in common is that going for a short walk after eating makes a big difference. That's not always possible, though, when busy on a deadline.
The good news, says Inchauspe, is that you can work out at any time up to 70 minutes after the end of your meal to curb a glucose spike. "Seventy minutes is around the time when that spike reaches its peak, so using your muscles before that is ideal."
It's not only walking: you can also use your muscles acutely in a push-up, a squat, a plank, or any weightlifting exercise. Resistance exercise (weight-lifting) has been shown to decrease the glucose spike by up to 30 per cent and the size of further spikes over the following 24 hours by 35 per cent.
I worry that all these constant spikes from sitting at work eating will be doing me harm. Inchauspe reassures me: "Harm is a spectrum – I think I would rephrase to say you may be able to feel better if you flatten those curves, for sure, and you would help your body, but you could also see much worse spikes and do your body even more harm."
So I will still enjoy the occasional croissant, but you might catch me doing 10 push-ups in the office afterwards.
Could a low carb diet be an effective treatment for diabetes?
Dr Arun Thiyagarajan, medical director of Bupa Health Clinics, explains ...
Is a low carb diet an effective treatment for diabetics?
We carry out thousands of diabetes tests every year, and are often asked by patients whether cutting carbs can help manage or prevent the condition.
While a low carb diet isn't an effective treatment for diabetes on its own, when implemented as part of a wider plan, it can have effective results. These include improved blood sugar management and weight loss, decreased medication needs and reduced the risk of diabetic complications.
How does it work?
For those who don't have diabetes, when we eat carbs, they're broken down into small units of glucose, which become blood sugar. When blood sugars go up, the pancreas produces the hormone, insulin, which then enters cells. For those with diabetes, the system doesn't work in the same way. People with diabetes are deficient in insulin or resistant to its effects. When individuals eat carbs, their blood sugar can rise this will trigger insulin release, which, if persistent, can render the body's cells less sensitive to insulin itself.
Therefore, reducing carb intake or following a low carb diet can help to manage the effects of diabetes, but should be used as part of a wider treatment plan to ensure sustainable changes.
What do you need to consider before commencing a low carb diet either to treat or to prevent diabetes?
It's important that you speak to your doctor before making changes to your diet or significantly reducing your carbohydrate levels. They'll be able to advice you on the best treatment plan and take into account the type of medication you are on to manage diabetes. For example, if you are on medication such as insulin – which can cause hypoglycemia – it is important that you don't cut out carbs. If you want to start reducing your carb intake, start with unhealthy sources such as pizzas, cakes and chips. To ensure you're still getting healthy carbs, look to replace them with healthy, high-fibre foods such as pulses, nuts, vegetable and whole grains.
For those who don't have diabetes, does losing weight via a low carb diet help to reduce risk of developing it in later life?
Being overweight is known to put you at greater risk of developing type 2 diabetes. As such, even for those who aren't diabetic, losing excess weight can help reduce the risk of developing the condition in the future.
Diet is an important factor, but it's not just about cutting down on carbs. A balanced diet can include carbohydrates, while cutting down on excess sugars and saturated fats. It should also be complimented by regular exercise, to ensure you're staying fit and healthy, while burning off calories from your diet. Our health advisers often hear from clients who are interested in trying out crash diets, and our advice is always the same.
Typically, these diets have short-term results, meaning people often put the weight back on. As such it's important that to make sustainable lifestyle changes, which will help maintain a more constant healthy weight, ultimately reducing the long-term risk of diabetes.