Quick summary
- After a meal, the glucose in our food is absorbed and enters the bloodstream, causing blood sugar levels to rise rapidly—this is called a glucose spike.
- 80% of people without diabetes experience high glucose spikes.
- Spikes in blood sugar levels can cause feelings of hunger, cravings, fatigue, and even have links to depression and fertility.
- Sustained high blood sugar levels contribute to increased ageing, stress, inflammation, as well as the risk of developing heart disease, Alzheimer’s disease, and type 2 diabetes.
- It is possible to keep blood sugar levels steady with a few simple hacks, such as having a savoury breakfast, eating sugar on a full stomach, and moving after a meal.
When we started writing this article, we imagined we’d be writing it specifically for people with type 2 diabetes. However, when we learned that 80% of people without diabetes experience high glucose spikes,[1] we realised that learning how to control blood sugar spikes is essential for absolutely everybody. So, read on and spread the word to your family and friends—the power of blood sugar is not to be overlooked.
What is a blood sugar spike?
Ever feel sleepy after a meal? Or eaten loads but felt hungry pretty soon after? Perhaps you’ve found it hard to concentrate on work after lunch? Well, that’s your blood sugar levels crashing back down after they’ve spiked. When we eat, the glucose (sugar) in our food is absorbed by the body and enters the bloodstream. This often ends up being quite a lot of glucose in one go, so our blood sugar levels rapidly increase, causing a spike (aka postprandial hyperglycaemia for the blood sugar nerds out there 🤓).
In a healthy individual, insulin is produced to shuttle this glucose around the body, lowering blood sugar levels and delivering fuel (in the form of glucose) to the body’s tissues. Sometimes so much insulin is produced that our glucose levels drop too low, and so we begin an unhealthy cycle of peaks and troughs in blood sugar levels. In those with type 2 diabetes however, not enough insulin is produced—or if it is, the body doesn’t respond properly, meaning blood sugar levels continue to climb. Elevated blood sugar levels in the long-term can cause complications all around the body but even these temporary blood sugar spikes after a meal can wreak havoc.
80% of people without diabetes experience high glucose spikes
It’s important to note that blood sugar spikes, particularly when eating foods high in carbohydrates, are a completely normal physiological response—whether you have type 2 diabetes or not. It’s the prolonged elevation of blood glucose levels that can be dangerous and can lead to disease over the long term, not a single spike. But even for those without type 2 diabetes, there are things that can be done to minimise how much your levels are spiking.
What do blood glucose spikes mean for the body?
In people with and without type 2 diabetes, spikes in blood sugar levels can cause hunger, a craving for high-calorie foods, and fatigue, and even have links to depression and fertility.[2-5] So, even if you’ve wolfed down a huge plate of pasta that really should fill you up, the rise and fall of your blood sugar may make you want to not only eat more, but to eat food that might not be the healthiest choice.
This happens because when your blood sugar levels crash back down, the cravings centre in the brain activates.[2] And guess what? With high-calorie processed food, your blood sugar levels will rise and fall again, and the greater the spike and fall, the hungrier you’ll be at your next meal.[3] It might sound like an endless cycle, but fear not... there are things you can do to help slow down how quickly your body absorbs glucose to keep your blood sugar levels stable.
In the grand scheme of things, frequent blood sugar spikes can go on to contribute to increased ageing, stress, and inflammation, as well as the risk of developing heart disease, Alzheimer’s disease, and, you guessed it, type 2 diabetes.[6-9]
For people with type 2 diabetes, recognising the symptoms of high blood sugar is a really important part of managing the condition. Symptoms of a blood sugar spike include:
- Frequent need to urinate
- Tiredness
- Increased thirst
- Blurred vision
- Headache
If you experience any of these symptoms, be sure to check your level and take appropriate steps to get it back down, such as hydrating and exercising. If you notice your blood sugar is spiking more frequently than usual, speak to your medical team as you might need to make changes to your treatment plan.
Now for the good news! 🙌
As we mentioned above, it is possible to steady glucose levels and we’ll talk about that in the next section but first, we want to tell you what limiting these spikes after a meal can do for your health:
- Reduce cravings a few hours later
- Make you less hungry at your next meal
- Reduce inflammation
- Slow down ageing
How to know if your blood glucose is spiking
If you’re curious to see if and how much your blood sugar levels are spiking after a meal, the best way currently is to wear a continuous glucose monitor (CGM), which will show you a chart of your levels across the day. With a CGM, you’ll be able to observe just how much different foods impact your glucose levels, as well as how quickly your body reacts to bring them back down to normal levels.
CGMs are available to purchase privately, and not everybody can afford them, so an alternative is using finger prick blood tests. These only tell you your levels at a certain point in time, so if you do use finger prick tests it’s best to try to be as consistent as possible—for example, to always do the test the same number of minutes after eating a meal.
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How to reduce spikes and keep blood sugars stable
These tips can help people with and without type 2 diabetes keep their blood sugar spikes to a minimum:
Start your day the savoury way
While the long-held belief that breakfast is the ‘most important meal of the day’ is up for debate,[10] there’s no doubt that the breakfast you choose can set you up for the day simply based on how it affects your blood sugar. A sugary start will cause a big spike in your blood sugar levels, while a savoury meal will keep levels steadier—this can determine your cravings and hunger pains for the rest of the day.[11]
Lots of ‘healthy’ breakfast cereals actually contain a lot of hidden sugar, so while you think you’ve made a healthy choice—muesli and yoghurt for example—your body will still be hit with a big rush of sugar. So, if you’re used to reaching for the cereal, a slice of toast with jam, or even a fruit smoothie, think about adding some savoury breakfasts to your morning—boiled or scrambled eggs on wholegrain toast, salmon and cream cheese bagels, avocado toast. Bonus points if you can sneak in a portion of whole fruit as well!
Eating your meal in a certain order could reduce the glucose spike after eating by as much as 73%
Save the bread for last
This might sound like an odd one but hear us out—by eating the contents of your meal in a certain order you could reduce the glucose spike after eating by as much as 73% and the insulin spike by 48%. [12] Certainly, research has shown that saving the bread (or rather, all carbs) ‘till last can help stop your post-meal peak. [12,13] In fact, the effect it has is comparable to the effects of medications that target post-meal glucose spikes.[12] Now, we’re not saying that you need to give up your meds by any means but it’s another tick in the box for the power of diet. Research into food ordering is still quite limited so work is ongoing but it could help people with type 2 diabetes manage their glucose spikes without getting too tied up by ‘how much’ or ‘what not to eat’ lines of advice.
🥬 Eat your veggies first to coat the lining of the intestine with their fibre, reducing how much glucose is absorbed.
🧀 Follow up with protein and fat—these will slow down how quickly the food moves from the stomach to the intestine (where absorption happens).
🍰 Finish your meal with, perhaps quite literally, the cherry on the cake: starch and sugar!
With the intestines lined with fibre and food arriving at a slower rate for absorption, blood glucose levels will rise gradually rather than rush in and cause a spike.
We’re not saying that you have to eat all your meals in this order (it's not always practical) but it’s certainly no bad thing to keep it in mind. Even the effects of a bowl of pasta can be mitigated slightly by eating a salad course first!
Eat sugar on a full stomach
Dessert is the last course of a meal but it might be beneficial to take this mindset with you for all things sugar. There’s no doubt that sugar causes blood glucose to rocket but its rate of absorption can be slowed down if you eat it with a full stomach. While your intestines are busy absorbing all the other goodness from your food, the sugar will be absorbed at a much slower rate. So, if you fancy a sweet treat, try to eat it after one of your main meals rather than in isolation.
Stick to whole fruit
We talk about this a lot and we’re going to carry on because it’s really important, especially for people with type 2 diabetes. First up, just because you have type 2 diabetes doesn’t mean you should turn your back on fruit entirely! Fruit is good for everyone—it contains tonnes of healthy vitamins and minerals, as well as natural fibres. Sure, fruit is sugary but as natural sugar its vastly better than the processed sugar found everywhere else.
That being said, it’s really important to eat whole fruit—an apple (skin and all!), an orange, a peach, cherries, the choice is yours, just make sure it’s the real (whole) deal and eat small portions throughout the day. Juices and smoothies might sound healthy but they contain a lower amount of healthy nutrients and a much higher dose of (not always natural) sugar, meaning your blood sugar levels will rocket.
Move after your meal
Gentle movement after you eat can help get your glucose levels back down as blood sugar is taken up by muscles for fuel. Research suggests that a walk after dinner, often the biggest meal of the day, can significantly reduce blood sugar levels for the next 24 hours.[14] So, walk, move, dance, tidy up, wash the dishes, vacuum, go up and down the stairs—just 10 minutes can make all the difference and not just for your blood sugar, but for your heart and mind, too.
Spike alert! 👀
This list is by no means exhaustive but you might find it a helpful reference point when thinking about foods that can cause your blood sugar levels to spike:
- Dried fruit
- Fruit smoothies
- Acai bowls
- Fruit/breakfast bars
- Low-fat fruit yoghurt
- Jam
- Sugary drinks
- Breakfast cereals
The effect elevated blood sugar has on the body is huge and as we’ve seen, it can affect both people with and without type 2 diabetes. But the good news is, we can use the amazing power of diet to keep things under control.
References
[1] Hall, H., Perelman, D., Breschi, A., et al. (2018). Glucotypes reveal new patterns of glucose dysregulation. PLoS Bio 16(7):e2005143. Accessible here.
[2] Page, K.A., Seo, D., Belfort-DeAguiar, R., et al. (2011). Circulating glucose levels modulate neural control of desire for high-calorie foods in humans. J Clin Investig 121(10):4161-9. Accessible here.
[3] Wyatt, P., Berry, S.E., Finlayson, G., et al. (2021). Postprandial glycaemic dips predict appetite and energy intake in healthy individuals. Nat Metabol 3:523–529. Accessible here.
[4] Breymeyter, K.L., Lampe, J.W., McGregor, B.A., Neuhouser, M.L. (2016). Subjective mood and energy levels of healthy weight and overweight/obese healthy adults on high-and low-glycemic load experimental diets. Appetite 17(1):253-259. Accessible here.
[5] Chavarro, J.E., Rich-Edwards, J.W., Rosner, B.A., Willett, W.C. (2007). A prospective study of dietary carbohydrate quantity and quality in relation to risk of ovulatory infertility. Eur J Clin Nutr 63:78-86. Accessible here.
[6] Kim, C-K., Park, S., Junghyun, K. (2017). The role of glycation in the pathogenesis of aging and its prevention through herbal products and physical exercise. J Exerc Nutrition Biochem 21(3):55-61. Accessible here.
[7] Picard, M., Juster, R-P., McEwen, B.S. (2014). Mitochondrial allostatic load puts the 'gluc' back in glucocorticoids. Nat Rev Endocrinol 10:303-310. Accessible here.
[8] Pahwa, R., Goyal, A., Bansal, P., Jialal, I. (2021). Chronic Inflammation. StatPearls [Internet] Accessible here.
[9] Standl, E., Schnell, O, Ceriello, A. (2011). Postprandial hyperglycemia and glycemic variability: should we care? Diabetes Care 34(Suppl 2):S120-S127. Available here.
[10] Spector, T. (2020). Spoon-Fed: Why almost everything we’ve been told about food is wrong, Jonathan Cape, London.
[11] Shukla, A.P., Iliescu, R.G., Thomas, C.E., Aronne, L.J. (2015). Food order has a significant impact on postprandial glucose and insulin levels. Diabetes Care 38(7):e98-e99. Accessible here.
[12] Chang, C.R., Francois, M, E., Little, J.P. (2019). Restricting carbohydrates at breakfast is sufficient to reduce 24-hour exposure to postprandial hyperglycemia and improve glycemic variability. Am J Clin Nutr 109(5):1302-1309. Accessible here.
[13] Nishino, K., Sakurai, M., Takeshita, Y., Takamura, T. (2018). Consuming Carbohydrates after Meat or Vegetables Lowers Postprandial Excursions of Glucose and Insulin in Nondiabetic Subjects. J Nutr Sci Vitaminol (Tokyo) 64(5):316-320. Accessible here.
[14] Borror, A., Zieff, G., Battaglini, C., Stoner, L. (2018). The Effects of Postprandial Exercise on Glucose Control in Individuals with Type 2 Diabetes: A Systematic Review. Sports Med 48:1497-1491. Accessible here.
