On Food and Your Blood Sugar
9-minute read•January 28th, 2019
Unless you’re diabetic, you probably aren’t paying close attention to your blood sugar level. And because you aren’t, you’re unlikely to make the connection between the contents of your lunch and how energetic you feel in the afternoon. Understanding how your food, your blood sugar, and your energy levels are connected, can help you make better food choices. And you’ll get some further health benefits that the future You will appreciate.
Why care about your blood sugar level?
Energy fluctuations throughout the day can be a nuisance, especially when you’re trying to be productive. But in the long run, they can also be a serious health risk, because they’re a direct reflection of blood sugarBlood sugar is the concentration of glucose in your blood. Since glucose is the preferred energy source for your body and we constantly need energy, there’s always a good amount of glucose in your blood. fluctuations.
Under normal circumstances, your body has a way of keeping blood sugar level within a healthyA healthy blood sugar level is less than 100 mg/dL after eight hours of not eating, and less than 140 mg/dL two hours after eating. range. However, regular and significant spikes in your blood sugar can affect this function over time. Proactively managing your blood sugar level can help you prevent this and lower your risk of developing type 2 diabetes, heart disease or age-related eye diseases.Source:Nutrition Reviews Not to mention, you’ll finally say goodbye to that afternoon slump.
Food and your blood sugar
Many factors can affect your blood sugar, and food is a major one. On the one hand, not eating for more than 4-5 hours will naturally cause your blood sugar level to drop. On the other hand, when you do eat, the nutritional contents of your meal have a big impact on how much and how quickly your blood sugar level will rise. Especially when your meal contains carbs.
Your body breaks down carbs from your food into glucose, the simplest form of sugar. Glucose that enters your blood after digestion is what we call blood glucose, or blood sugar. The simpler the carbsSimple carbs are carbs, whose molecules are made up of 1-10 ‘sugar units’. Glucose is a simple carb that contains one sugar unit. Carbs with more than 10 sugar units are considered complex. you eat, the easier for your body to break them down into glucose and the sharper the increase in your blood sugar. More complex carbs take longer to break down, which is why they only increase your blood sugar gradually.
If your blood sugar gets too high, it can be dangerous or even fatal. That’s why every time your blood sugar rises, your body responds by producing insulin. Insulin is a hormone that helps remove glucose from your blood and distribute it to your tissues. The amount of insulin your body produces after a meal depends on how quickly and how much your blood sugar level is rising. That’s why a meal loaded with simple carbs results in extra insulin production, which causes your blood sugar level to drop as sharply as it rises. And with it, down goes your energy level.
Although carbs have the most direct effect on blood sugar, protein and dietary fats can also cause fluctuations. They do that by triggering increased insulin production. And increased insulin production always brings your blood sugar level down. Protein in isolation affects your insulin production only slightly, and dietary fats in isolation – not at all. However, fats and protein consumed together with carbs can almost doubleSource:University of Sydney the insulin response of carbs alone. Therefore, to fully understand and manage blood sugar fluctuations, it’s not enough to only look at carb content in foods.
Tools for blood sugar control
If you want to keep your blood sugar in control, there are three main tools you can use – the glycaemic index (GI), glycaemic load (GL) and insulin index (II). All three are values assigned to foods on the basis of how quickly and how much these foods raise your blood sugar and/or insulin levels. Let’s look at them individually.
1. Glycaemic index (GI)
The glycaemic index (GI) measures how carb-containing foods affect your blood sugar when compared to glucose. Why glucose? As the simplest form of sugar, it raises your blood sugar level to the greatest and fastest extent compared to other foods. This makes it a practical reference point.
The GI value assigned to glucose is 100 and it’s the maximum GI value possible. The closer to 100 a food scores, the sharper the blood sugar fluctuation it will cause after consumption.
Below is a non-exhaustive list of popular foods grouped by their GI values:
|GI value||Examples of foods|
|<55 (low GI)||Beans (black, kidney, lentils, peanuts, chickpeas); small seeds (sunflower, flax, pumpkin, sesame); nuts (walnuts, cashews); most whole intact grains (wehat, oat, rye, rice, barley); most vegetables and most sweet fruits (peaches, strawberries, mangos).|
|56-69 (medium GI)||White sugar; basmati rice; unpeeled boiled potato; grape juice; cranberry juice; raisins; prunes; banana; sweet potato.|
|>70 (high GI)||Glucose; high fructose corn syrup; white bread; most white rice; white potato.|
2. Glycaemic load (GL)
The glycaemic load (GL) is a value based on the glycaemic index. However, the GL is the more practical tool of the two, because it takes into account the serving size of food. For example, watermelon has a high GI. However, due to its significant water content, the amount of available carbs found in a normal serving of watermelon is actually low, which also results in a low GL value. What does that mean? Despite watermelon’s theoretical potential to cause a spike in your blood sugar level, it’s unlikely to cause it in practice if you eat a normal serving size (a slice or two). Therefore, regardless of their GI score, if you stick to low-GL foods, you’ll avoid big blood sugar and energy fluctuations.
For a single serving of food, a GL value is considered high if it’s more than 20, medium if between 11-19, and low if 10 or less. Below are some common foods and their GI and GL values:
|Food||GI||GL (per 100g)|
|Baguette (white, plain)||95||48|
|White rice (boiled)||64-93||16-23|
3. Insulin index (II)
A major disadvantage of GI and GL is that they only measure the effects of carb-containing foods on blood sugar. However, foods that hardly contain any carbs can still trigger insulin production and lower your blood sugar as a result. This can make you feel hungry and less energetic soon after a meal. Sustained over the long run, high levels of insulin production can lead to impaired glucose toleranceImpaired glucose tolerance (IGT) is a state characterized by hyperglycemia (high blood sugar) and increased risk of cardiovascular disease. IGT is also a risk factor for mortality., high blood pressure and, eventually, increase your risk of developing type 2 diabetes.
So, to manage your blood sugar and energy levels efficiently, you need to consider how food affects your insulin response. The insulin index (II) addresses this and applies to all foods, regardless of their carb content.
Because the II is more comprehensive than the GI or GL, it has the potential to be a more useful blood sugar control tool than the other two. As the most recently introduced index of the three, II has the disadvantage of being less researched to date. However, the existing studies are positiveSource:University of Sydney it can play a role in insulin and blood sugar control for both healthy and diabetic individuals.
Similar to GI and GL, the highest possible II value is 100, assigned to glucose. The lower the II of a certain food, the smaller the effect it has on your energy and blood sugar levels.
These are the insulin indexes of some common foods:
|Food||Insulin index (II)|
|Potato (peeled and boiled)||88|
|White fish fillet||43|
|Roast chicken, without skin||17|
This is what you should keep in mind about food and your blood sugar:
- The food you eat affects your blood sugar and energy levels. Simple carbs cause bigger fluctuations than complex carbs. Dietary fats and protein in your meal can also affect your blood sugar by raising your insulin production.
- High blood sugar and insulin levels over time can lead to impaired glucose tolerance and increase your risk of developing type 2 diabetes, heart disease and age-related eye diseases.
- The glycaemic index (GI), glycaemic load (GL) and insulin index (II) are all values assigned to foods based on how much and how quickly they raise your blood sugar and/or insulin levels after consumption.
- By sticking to low-GL and low-II foods in your diet, you can prevent sharp blood sugar fluctuations. This will lead to a stable energy level throughout the day and help you prevent diseases in the future.