Why Blood Glucose is the Best Biomarker and How To Influence It

Tracking your blood glucose levels on your phone

How can you know if your lifestyle is keeping you healthy? Is that apple a day really keeping the doctor away? Are 7 hours’ sleep per night really enough, or should you really be getting 8? And is that banana you have before your morning run actually helping you go the extra mile? Or is it creating more problems than it solves? The answers lie in the biomarker ‘blood glucose’.

For centuries, the workings of the human body were something of an enigma. Everything was always fine until our body lets us know that it wasn’t, and by the time that happened, often it was too late. Fortunately, in the 21st Century that has started to change. For the first time in history, technology and data analysis apps have made people’s individual health data more readily available than ever before. This allows them to react to health problems they’re already having. And makes it possible to actually take preventative actions to stop them in their path.

However, the abundance of data and information relating to health in the modern world can present a problem. Which data should you be following? How should you be measuring it? And how can you accurately interpret its results?

In this post, we’ll be taking a look at ‘biomarkers’ – the tell-tale sign that something is happening in your body.

We’re going to explore:

  • which biomarkers you should be aware of
  • how you can measure them
  • and in particular why there’s one biomarker that you should be focusing on more than any other: blood glucose.

Hello Inside Podcast with Tim Böttner: Practical insights about CGM and glucose monitoring

Why blood glucose is the best biomarker

There are a number of different biomarkers that you could choose to monitor to get an idea of your overall health. However, none of these are as effective, as thorough, or as medically insightful as measuring your blood glucose levels. Let’s explore why the biomarker ‘blood glucose’ is so valuable compared to others.

Your Heart Rate, and thus your Heart Rate Variability (HRV), is also an important biomarker to keep an eye on. This is particularly important if there’s a history of cardiovascular problems in your family. HRV is the time interval between each of your heartbeats. This can be used to show whether or not your heart is functioning regularly. An irregular heartbeat can be caused by increased stress, hormones, a lack of sleep, or can be a sign of metabolic dysfunction. Yet while your HRV might be a good indicator if there is something wrong, it won’t do anywhere near as much to tell you what the problem might be as measuring your blood glucose levels.

Smartwatches and other smartphone apps have also made measuring sleep popular in recent years. The quality, quantity, and consistency of sleep are all significant variables. Getting enough sleep is essential to your well-being, fitness, and immune function. It’s true that chronic sleep deprivation can lead to obesity, heart disease, high blood pressure, and diabetes. However, just monitoring sleep may not be a strong enough indicator of general health, as they offer few insights into what’s going on inside your body.

Blood glucose levels are the best biomarker by which to measure your overall health, simply because of the depth and range of insights that they can offer. Here are some of the things they can help you identify:

Spikes, crashes and glycemic variability

Frequent increases and decreases in your blood glucose levels can make daily life a nightmare, but the chances are you’re already suffering from them in silence. Do you often feel fatigued, find it hard to focus, or feel low, unproductive? Are you constantly hungry? These are all signs of having unstable blood glucose. Finding ways to stabilize them could be the first step towards living a healthier, happier, and easier life. In the long term, frequent spikes and crashes in your blood glucose can even lead to chronic diseases such as cancer, stroke, and cardiovascular disease, as well as cognitive decline.

Your unique reaction to different foods

There’s no room for one-size-fits-all diet and nutrition plans in the 21st Century. Now we know that everybody’s bodies are completely unique, and react to foods in different ways. Monitoring how your blood glucose rises and drops in response to the different foods you eat will give you the definitive answer you need to know whether you can have that extra cookie or should be cutting down on carbs. Your blood glucose levels reflect the state of your microbiome (the bacteria living in and on us) and the influence of your genes, fitness level, sleep patterns, stress, and diet on your overall health. This offers you unparalleled insight into the shape your body’s in and what you can do to improve it.

Metabolic flexibility

Nowadays we know that managing your weight is a lot more nuanced than a simple equation of the number of calories consumed minus the number of calories burned. When you have high levels of glucose in your blood, your body will use this as its preferred source of energy. This means any excess calories get stored as fat and lead to weight gain.

When your blood glucose levels are stable, your insulin sensitivity increases. Insulin resistance is something you want to avoid because it means that your cells don’t respond well to insulin, can’t use the glucose from the blood, and make the blood glucose levels go up. So when the resistance decreases your body is able to process the glucose in your blood and start burning fat faster, preventing weight gain. In other words, knowing how to stabilize your blood glucose allows you to eat in a way that trains your body to be more metabolically flexible, keeping you within your desired weight range.

Metabolic dysfunction

Not having access to readily available biomarkers by which to measure your overall health has meant that in the past, it’s often been impossible to spot the onset of metabolic dysfunction before insulin resistance develops, which means it’s too late. Measuring your blood glucose as a biomarker can already start to give you insights that you otherwise might have missed. Insulin resistance, for example, is one thing that could take 10 years to show up in a blood test, but that you can already catch by monitoring your blood glucose regularly. Making the right changes to your diet and lifestyle can be crucial to preventing the onset of pre-diabetes and other chronic conditions.

How do you measure your blood glucose?

The most reliable and readily available way to measure your blood glucose is by using a Continuous Glucose Monitoring device (CGM).

A CGM is a small and discreet white disc, no larger than a €2 coin, which is placed on the back of your arm and can comfortably be worn under clothes. It will also stay on while swimming, showering, or performing any of your daily activities as usual.

Your CGM will be busy monitoring the glucose levels in your blood. You can check these at any time by using the Hello Inside App, which uses NFC technology in your smartphone to transfer the information from the device. The Hello Inside App will help you to identify trends in your glucose levels, as well as spikes and crashes, and guide you to making healthy lifestyle adjustments that can help to keep your blood glucose levels stable and in the healthy range. Check out our Look Inside Kit.

Blood glucose response curve after an event explained

What are healthy blood glucose levels?

Blood glucose is measured in milligrams per decilitre (mg/dL). Healthy blood glucose levels in the Hello Inside App are defined as anywhere within the range of 80-110 mg/dL during the day.

Doing any physical activity, feeling stressed, or eating certain foods can cause your blood glucose levels to temporarily spike. Monitoring your blood glucose levels can help train you to understand what causes your blood glucose to spike in particular, and then work to try and avoid these triggers.

What are bad levels?

Your blood glucose levels will always be in constant flux throughout the day and night but should remain within a certain healthy range (see above).

If your blood levels drop too low or go too high, especially after a meal (pictured as dip and spike), this could potentially be dangerous and a cause for concern. Generally speaking, frequent crashes below 60 mg/dL or spikes above 180 mg/dL are considered potentially dangerous.

If your blood glucose levels are consistently hovering around either of these two values, this could be an indicator of a more serious underlying problem and you should seek medical advice.

What are signs of good or bad blood glucose levels?

When your blood glucose levels are healthy, you feel great! You don’t experience hunger shortly after finishing your last meal or find yourself having any cravings. Equally, you feel energized, happy, can easily focus, and do what you need to do.

Signs that your blood glucose levels are not within the healthy range can be feeling irritable, hungry, tired, having trouble concentrating on specific tasks, or start having symptoms of depression and anxiety.

Our blood glucose levels fluctuate throughout the day, particularly after eating or doing exercise. This means you may experience spikes or crashes at any time, including while you’re at work. If you suddenly feel like you’re having the worst day ever and that all your co-workers’ IQ levels suddenly dropped by 20 points, it might be a good idea to check your blood glucose before you start drafting your resignation letter.

What is success with blood glucose in the short and long term?

Successfully stabilizing your blood glucose levels means keeping them within a healthy range. This also means no longer having to live with unpredictable mood swings, low energy, brain fog, lack of focus and concentration, hunger, cravings, and general daily psychological and physical discomfort.

In the long term, successfully stabilizing your blood glucose levels also means preventing the onset of metabolic dysfunction and chronic diseases such as diabetes, cancer, stroke, bodyweight issues, and other conditions that could significantly impact your life expectancy and quality of life.

How can I influence my blood glucose levels?

There are many things you can do to directly or indirectly influence your blood glucose levels.

You can directly influence your blood glucose levels through nutrition and your exercise regime. Eating the right or the wrong foods, and exercising too much or too little are all things that will directly impact the score you see when you check your blood glucose levels.

However, there are many things that you may or may not already be doing which can indirectly influence your blood glucose levels. These include things like your sleeping pattern, whether or not you’re more or less stressed than usual, and addictive substances such as nicotine and alcohol.

To understand these better, we’ve divided up everything that can, directly and indirectly, influence your blood glucose levels into 6 different lifestyle pillars. You can use those to influence your biomarker score and train your body to have a healthier relationship with blood glucose.

Six lifestyle pillars for stable blood glucose levels

The 6 lifestyle pillars to healthier blood glucose


Your diet directly impacts your blood glucose levels. This is all about the foods you eat, portion size, and even the order in which you eat them. You probably already knew that eating sugar can spike your blood glucose levels. But did you know you can reduce this effect by only eating sweet things after a healthy, balanced meal? 

The ‘Apple Cider Vinegar’ hack

If you find yourself regularly having blood glucose spikes after eating certain foods, such as carbohydrate or sugar-heavy dishes like pasta or cake, you can actually lower the impact this can have on your blood glucose levels by consuming a small amount of apple cider vinegar before. Die-hard fans might carry a supply of the stuff around in a hip flask, but just having a small green salad with an apple cider vinegar dressing before a heavy meal can make a big difference. Try it and monitor your blood glucose levels to see how they respond!

Physical Activity

Keeping active and moving throughout the day is essential to allow your body to process the glucose in your blood, and support your insulin metabolism. Going for a short walk after a heavy lunch can do wonders to keep you focused and energized throughout the afternoon. You may even find you can skip your afternoon coffee!


Making sure your body is fully rested each day is vitally important. Did you know that your blood glucose levels are higher after a bad night’s sleep? Sleep allows your body to recover from the stress of the day before. It’s essential for making sure that your body can continue to process glucose and burn energy from the correct sources. Try to get into good habits when it comes to your sleeping pattern by setting a regular, early bedtime. Avoid doing anything too stimulating in an hour or so before you hit the hay. Switching off all screens and limiting your exposure to artificial light can help a lot. There are so many ways you can fall asleep without looking at a screen. When was the last time you read a book? Or listened to a podcast?


Humans are innately social animals, which means that we depend on the company of others to feel healthy and happy. Spending quality time with close friends and family can help us to feel less stressed, more energized and more like a part of a community. This indirectly has a positive influence on our blood glucose levels. But try not to let yourself get talked into eating unhealthy meals or drinking too much alcohol just in the name of socializing! If you notice any food pushers around you, just tell them about the sensor you’re wearing. Show them the effect certain foods had on your body. This will make for great conversations. 

Addictive substances

Drinking alcohol, particularly in excess, is bad news for your glucose levels. Amongst the many things that alcohol does while it’s in your system, your body will use it for fuel. This further delays it starting the process of burning glucose, and then eventually fat. There’s not much good news for smokers, either. Nicotine has also been shown to increase insulin resistance which raises your glucose levels and makes spikes more likely to occur. If you want to get serious about blood glucose as a biomarker, it’s time to quit smoking once and for all and try to cut down or cut out alcohol as much as possible. Yet, if you can’t resist a glass of alcohol at an event, opt for wine or champagne rather than cocktails or beer.


Stress releases cortisol which impairs the way glucose can be used by the cells and raises your blood glucose levels. In other words, if you’re stressed, you’re probably not feeling very healthy or happy either. Firstly, try to cut down on any foods in your diet that may be triggering internal stress, such as caffeine and sugar. Secondly, try to develop some external stress-coping strategies to deal with external influences in your daily life. These can be breathing exercises, meditation, sipping a mug of hot tea while staring wistfully out the window, or running a nice warm bath. Essentially, anything that counts as ‘you-time’ can help bring your stress down, and your blood glucose levels with it.

How do I start managing my blood glucose levels?

Some of the lifestyle changes you’ll need to make to see a meaningful difference might be harder to stick to than others. As with all new habits, the best way to make them last is to start small. Gradually work towards implementing them across all areas of your life. Also, make sure that you’re constantly tracking your progress and setting incremental goals to really make sure you succeed.

know you body like no one else - Hello Inside

Hello Inside Team

We have a passion for health, wellbeing and lifestyle topics. We love to discover new things and get to know ourselves better. Transforming scientific knowledge and insights into actionable advice is our goal.

more posts from author

Hello Inside Team

We have a passion for health, wellbeing and lifestyle topics. We love to discover new things and get to know ourselves better. Transforming scientific knowledge and insights into actionable advice is our goal.

more posts from author

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