Updated: Sep 14, 2022
The glycemic index (GI) is a metabolic tool to promote effective blood sugar management.
You see, each food has its glycemic index. The glycemic index of every food is influenced by several factors, such as the cooking method, nutrient composition, ripeness, and the level of processing the food has undergone.
By knowing the glycemic index of the food you’re eating, you can be sure whether the food will enhance weight loss, reduce cholesterol levels, or decrease sugar levels in your blood.
In this article, we will examine the glycemic index in detail. We will learn the glycemic index, its effect on your health, and the right way to use it.
Let’s define the glycemic index.
The glycemic index of a food is a measure of its ability to increase your blood sugar level. So, the glycemic index of a food tells you to what extent food can increase your blood sugar level.
GI may be low, medium, or high. It is usually ranked on a scale of 0 – 100. A particular food with a low GI will have a lesser effect on your blood sugar level (1).
Here’s how the GI is rated:
Low GI: ≤ 55
Medium: 59 – 69
High: 70 or above
Foods high in sugar and refined carbs are digested faster than protein-rich, fatty, or high-fiber foods. Also, foods with high sugar content and refined carbs have a higher glycemic index than protein-rich, fatty, or high-fiber foods. No GI is assigned to foods without carbs. Examples of foods without GI include oils, spices, herbs, seeds, nuts, poultry, fish, and meat.
The GI of a particular food is also influenced by factors like cooking method, ripeness, sugar content, and the extent to which the food has been processed (2).
It is important to note that the glycemic index differs from the glycemic load.
The Glycemic index doesn’t consider how much food you’ve eaten. Conversely, the glycemic load thinks the number of carbs in each serving. With this, it can determine whether that food will affect your blood sugar level or not (1).
This explains why you should consider both the glycemic index and the glycemic load of your preferred foods. Doing so will help you choose healthy foods that keep your blood sugar at healthy levels (1).
Now, let’s look at the low glycemic diet.
The low glycemic diet involves replacing high GI foods with low GI foods.
What are the benefits of a low glycemic diet?
A low glycemic diet has many health benefits. These include:
Enhanced regulation of blood sugar: Several studies have shown that a low GI diet reduces blood sugar levels. It also helps better manage blood sugar in type 2 diabetics (3, 4).
It enhances weight loss: Several studies have found that a low GI diet improves short-term weight loss. However, there is a need for more studies to find out the effect of this diet on long-term weight management (5, 6, 7).
It lowers cholesterol levels: A low GI diet can reduce total and LDL cholesterol levels. It is important to note that both cholesterols constitute a risk for heart disease (8, 9).
What’s the right way to follow a low GI diet?
To follow a low GI diet correctly, you must eat more low GI foods.
Foods in this category include:
Non-starchy vegetables: cauliflower,
broccoli, carrots, tomatoes, and spinach.
Fruits: berries, lemons, apples, oranges, grapefruit, limes.
Whole grains: couscous, quinoa, buckwheat, oats, barley, and farro.
Legumes: kidney beans, black beans, lentils, chickpeas.
Foods with a low GI value or none can be eaten as a balanced low glycemic diet. Examples of these foods include:
Seafood: salmon, tuna, mackerel, sardines, anchovies, etc.
Meat: pork, lamb, bison, beef.
Poultry: goose, duck, turkey, and chicken
Herbs and spices: black pepper, turmeric, dill, cumin, rosemary, basil, and cinnamon.
Seeds: sesame seeds, chia seeds, hemp seeds, flax seeds.
Nuts: macadamia nuts, almonds, pistachios, and walnuts.
Oils: Coconut oil, vegetable oil, olive oil, avocado oil.
No foods are off-limits on the low GI diet, but you should limit the number of low GI foods you eat.
Foods that have a high glycemic index include:
Rice: jasmine rice, white rice, arborio rice
Bread: bagels, white bread, pita bread, naan
Cereals: breakfast cereals and instant oats
Noodles and pasta: ravioli, lasagna, macaroni, spaghetti, fettuccine
Baked goods: doughnuts, cake, cookies, muffins, croissants
Starchy vegetables: potatoes, mashed potatoes, French fries
Sweetened beverages: fruit juice, soda, and sports drinks
As much as you can, always try to substitute these foods for low GI foods.
What effect do cooking and ripening have on the glycemic index of foods?
Cooking can affect the glycemic index of certain foods. However, this is dependent on the cooking method.
Fried foods, for instance, contain more fat which can slow sugar absorption, thus decreasing the glycemic index (10, 11).
On the other hand, baking and roasting break down resistant starch and thus increases that food's GI. Resistant starch is difficult to digest. It is mainly found in potatoes, legumes, and oats (10, 12).
Boiling retains more starch and reduces the GI of food (10).
The longer you cook foods such as rice or pasta, the easier it is for that food to be digested. This translates to an increase in their GI. So, you’re better off cooking these foods until their texture becomes al dente (13, 14).
The ripeness of fruit also affects its GI. As the fruit ripens, the amount of resistant starch in it decreases. This results in a higher glycemic index (15).
The glycemic index of a food is a value that tells the extent to which a food can affect your blood sugar level.
The GI of a food is affected by several factors, such as ripeness, the type and amount of nutrients in that food, and the extent to which it has been processed.
Adopting a low glycemic diet can benefit your health in several ways. It maintains a healthy blood sugar level, reduces cholesterol, and helps with short-term weight loss.
Christian Frazier Certified Life Health & Nutrition Coach