Controlling blood sugar (a.k.a. glucose) is key to balancing several metabolic conditions – insulin resistance, metabolic syndrome, prediabetes and diabetes, and overweight and obesity. The glucose levels in your blood rise whenever you eat something. However, how much it will rise and the length of time that it will stay elevated depends on numerous factors. In this regard, two tools can help you balance and normalise your blood sugar levels. These tools are called glycemic index (G.I.) and glycemic load (G.L.); this article presents both in detail.
What is a glycemic index?
By definition, the glycemic index represents an incremental area under the blood glucose response curve elicited by a 50 grams carbohydrate portion of food expressed as a percentage of the response after 50 grams of anhydrous glucose taken by the same person.
Well, the above definition is highly complex and difficult to understand by people who aren’t scientists, people like me. In simple words, the glycemic index (G.I.) is a food rating system that rates individual foods (e.g., veggies, starches, dairy) on a scale of 1-100 based on their effect on blood sugar. It indicates how quickly the carbohydrates in a specific food get digested and absorbed. The higher a food is on the scale, the quicker the digestion process and the greater the effect on the blood sugar levels.
It’s important to mention that the glycemic index is a value that is independent of the portion size of the food or the amount of carbohydrates consumed. Also, the glycemic index is not the same as the glycemic response.
Different foods, different G.I. values
Depending on where on the scale foods are located, they can have a low, medium or high glycemic index value.
High G.I. foods have a measure between 70 and 100. After eating such foods, your glucose and energy levels will spike and then quickly drop. Examples of such foods include French fries, pretzels, doughnuts, corn flakes, bagels, biscuits, white bread, beer, gnocchi, lasagna noodles, plantains, sports drinks, potatoes, rice flour and watermelon.
Medium G.I. foods fall in the range of 56 to 69. Examples of such foods include brown rice, honey, whole grain bread, honeydew melons, papaya, oatmeal, raisins, long grain rice, sorbet, rye, spelt and vanilla ice cream.
Low G.I. foods have a rating of 55 or less. Your body digests these foods slowly and steadily. Foods with low glycemic index are whole oats, lentils, peanuts, apple, oranges, almonds, avocado, artichoke, asparagus, bananas, broccoli, cabbage, cherries, eggs, grapefruit, cashew, chickpeas, carrots, cucumbers, hummus, mango, milk, olives, plums, prunes, spinach, strawberries, and tomatoes.
Eating foods that are low on the G.I. scale could help you shed some unnecessary kilograms as those foods control the appetite by delaying hunger. In contrast, the consumption of foods with high G.I. values is likely to make you feel tired and hungry.
Is a low GI-based diet good for you?
Using the glycemic index when selecting your food for the day is a good way to identify how individual foods may affect your blood sugar levels, especially if you have concerns related to diabetes or other severe metabolic problems.
Following a low G.I. diet can help decrease blood sugar, inflammation, and insulin response. A decrease in inflammation can further reduce the risk of heart diseases. A low G.I. diet can also keep you feeling full longer and can be a helpful mechanism for weight management.
However, according to dieticians, adopting such a diet isn’t always reliable. A food’s G.I. value doesn’t usually consider how the food is prepared or processed or how ripe it is (e.g., a green banana has a lower G.I. value than a ripe banana). The G.I. value also doesn’t consider information about the other nutrients present in the food. For instance, whole milk has a G.I. value of 31, which is low on the glycemic index scale. But whole milk also has lots of fat, and consuming too much fat is unhealthy. So, just because an individual food has a low G.I. value doesn’t mean it is a good option for losing weight.
The bottom line, a low G.I. diet would work for you if you have a balanced approach, choose healthier foods and pay attention to the foods’ nutritional labels and serving size recommendations. It is important not to overeat with only carbs, fats or protein. And also, include exercising in your daily schedule. A 20-minute workout or a walk in the park will help you speed up the fat-burning process.
What is glycemic load?
The glycemic load (G.L.) is another way to categorise foods based on their impact on blood sugar levels. There are many scientific definitions for glycemic load as; the most common and easy to understand are as follows:
- G.L. is an indicator of a glucose response or insulin demand induced by the total carbohydrate intake.
- Glycemic load is a measure of dietary insulin demand.
G.L. takes into account the glycemic index (G.I.) and the portion size of foods. Thus, to calculate the glycemic load of individual foods, you need to take the food’s glycemic index value and multiply it by the grams of carbs in the food, then divide the total by 100. The lower the G.L. value, the smaller the food’s effect on your blood sugar levels.
Different foods, different G.L. values
Similarly to the glycemic index, G.L. also has three categories: low, medium and high:
- Low G.L. foods have a ranking of 10 or less. Examples of such foods include apricots, mango, oranges, apples, hummus, honey, salmon, avocado, grapes, watermelon, peanuts, bean sprouts and carrots.
- Medium G.L. foods fall in the range 11 – 19. For instance, white bread, low-fat yoghurt, orange juice, bananas, pizza, and apple juice.
- High G.L. foods have a measure of 20 or higher. E.g., cornflakes, oatmeal, candy bars, raisins, rice (brown and white), baked potatoes, chocolate chip cookies, muffins, soft drinks and pasta. The frequent consumption of high G.L. foods is linked to an increased risk of diabetes, cardiovascular diseases and colorectal cancer.
In addition, this categorisation method is mainly useful when choosing to eat individual foods. If two or more foods are eaten together, the overall glycemic load of the foods can change. For instance, bananas (depending on ripeness) have an average medium G.L. value of 14. If you put them on crackers with spread peanut butter and eat the whole thing, your blood sugar levels will rise very quickly.
How useful are the G.I. and G.L. scales?
Both tools – glycemic index and glycemic load – can be used as a base for developing various recipes and planning meals for a day or week ahead. They can help you choose foods low on the glycemic load and pair them with foods low on the glycemic index scale or other low G.L. foods. Additionally, if you pay attention to the nutritional labels on the packaged foods, using either or both of these tools will help you make better and healthier choices.