What is the glycemic index? Which type of carbohydrates should be included?
Glycemic index and load
Carbohydrates (carbs) are the primary food that raises blood sugar. Glycemic index and glycemic load are scientific terms used to measure the impact of a carbohydrate on blood sugar.
- Foods with low glycemic load (index) raise blood sugar modestly and thus are better choices for people with diabetes.
- The main factors that determine a food's (or meal's) glycemic load are the amount of fiber, fat, and protein it contains.
- The difference between glycemic index and glycemic load is that glycemic index is a standardized measurement and glycemic load accounts for a real-life portion size. For example, the glycemic index of a bowl of peas is 68 (per 100 grams) but its glycemic load is just 16 (lower the better). If you just referred to the glycemic index, you'd think peas were a bad choice, but in reality, you wouldn't eat 100 grams of peas. With a normal portion size, peas have a healthy glycemic load as well as being an excellent source of protein.
Carbohydrates can be classified as either
- complex carbohydrates, or
- simple sugars.
1. Complex carbohydrates (low glycemic load foods, or foods that are a part of a type 2 diabetes plan) are in their whole food form and include additional nutrients such as:
- Smaller amounts of proteins and fats
These additional nutrients slow down the absorption of the glucose and keep blood sugar levels more stable.
Examples of complex carbohydrates, or low glycemic load (index) foods include:
- Brown rice
- Whole wheat
- Steel-cut oatmeal
Grains and starchy vegetables
Whole grains, such as brown rice, quinoa, and oatmeal are good sources of fiber and nutrients; and have a low glycemic load making them good food choices. Processed food labels make it very confusing to understand whole grains. For example, "whole wheat bread" is made in many different ways, and some are not that different from white bread in its blood sugar impact (glycemic load). The same is true for whole grain pasta, it's still pasta. Whole grains have less of an impact on blood sugar because of the lower glycemic load. Choose whole grains that are still in their grain form like brown rice and quinoa, or look at the fiber content on the nutrition label. For example, a "good" whole grain bread will have 3+ grams of fiber per slice.
Starchy vegetables that are good sources of nutrients like vitamin C, and that are higher in carbohydrates than green vegetables, but lower in carbs than refined grains. They can be eaten in moderation. Starchy vegetables include:
- Other root vegetables
The above starchy vegetables are best eaten in smaller portions (1 cup) as part of a combination meal that includes protein and plant-based fat.
Non-starchy vegetables, such as green vegetables, can be eaten in abundance. These foods have limited impact on blood sugar, and also have many health benefits, so eat up! Almost everyone can eat more vegetables - we need at least five servings a day.
Fresh vegetables are a great option, and usually the tastiest option. Studies show that frozen veggies have just as many vitamins and nutrients because they are often frozen within hours of harvesting. Just check to make sure there aren't added fats or sweeteners in the sauces that are on some frozen veggies. If you don't like vegetables on their own, try preparing them with fresh or dried herbs, olive oil, or a vinaigrette dressing. Aiming to consume a rainbow of colors through your vegetables is a good way to get all of your nutrients.
2. Simple carbohydrates (high glycemic load foods, or foods that are not part of a type 2 diabetes diet plan because they raise blood sugar levels) are processed foods, and don't contain other nutrients to slow down sugar absorption and thus these foods can raise blood sugar dangerously fast. Many simple carbohydrates are easily recognized as "white foods."
Simple carbohydrates or high glycemic index foods that should not be included in your diet, for example::
- White pasta
- White bread
- White potatoes
- Breakfast cereals
- Pastries and sweets
- Fruit juice
- Soft drinks