Some food companies are now labeling their products as low glycemic index or low GI. What is the glycemic index? What effect does it have on your health and energy levels? And, how can you lower the GI of the foods you eat? That’s the focus of this blog. If you prefer you can skip the text and just watch the two-part simplified animated white board videos down below.
What is the Glycemic Index?
Glycemic index is a measure of how quickly blood sugar (or more technically, blood glucose) rises after eating particular foods.
Carbohydrates, upon digestion, break down into glucose molecules that the body uses for energy. Proteins and fats do not break down into glucose. Therefore, the glycemic index only refers to foods that contain carbohydrates.
So, don’t go throwing out all carbs in an attempt to lower the glycemic index. Glucose from the carbs is fuel for our body. It’s what our brain runs on. And, when we exercise we burn a large percent of our fuel needs from carbohydrates. In addition, carbs are rich in nutrients you can’t find in other foods like fiber, and certain vitamins and minerals.
Again, when we talk about glycemic index, we’re only talking about foods that contain carbohydrates including:
- Grains (including wheat, corn, quinoa, oats)
- Beans (such as kidney beans, chick peas, black beans)
- Milk, yogurt, ice cream
- Fruits and vegetables
- Sugars (agave, beet, cane, maple and more)
- Fruit juices (such as 100% orange, apple, and fruit drinks)
- Sweet drinks (sodas, sports drinks, sweetened ice tea)
When people say that meat and oils are low glycemic, that’s not really accurate. They don’t have carbohydrates so the glycemic index doesn’t even apply to them.
Are Lower GI Foods Healthier?
No, not necessarily. There are so many examples of lower GI foods that are certainly not healthier overall than higher GI foods. For example, ice cream has a lower GI than whole grain bread.
The glycemic index is just one factor to consider if you’re watching your health, weight, blood glucose, and energy level. In fact, you’ll soon discover that there are certain situations in which a higher glycemic index food is more preferable than a lower GI food. But, I’m getting ahead of myself.
Benefits of Lower Glycemic Index Foods
Low GI foods:
- Lower fasting glucose and insulin – which might help people with diabetes. But, might also help people who experience reactive hypoglycemia or low blood glucose
- May also help increase satiety, in other words make us feel full longer which may then help people manage their body fat
More About the Glycemic Index
Here’s how scientists came up with the glycemic index. After you eat foods containing carbohydrates, it gets digested in your gut into tiny glucose molecules…which are then small enough to pass into the blood stream.
In order for glucose to get into the cells, we need insulin, a hormone produced by the pancreas. The higher the glucose level in your bloodstream, the more insulin your pancreas secretes.
All of this happens within 2 hours after eating carbohydrates. But not all carbs take the full two hours. Some are absorbed much faster than that.
The GI Scale: High, Medium, and Low GI
The glycemic index was designed to rate how quickly equal amounts of carbohydrates are absorbed. Typically, a scale of 0-100 is used with white bread having a score of 100.
- Low GI foods are absorbed slowly, taking perhaps the full 2 hours…so the blood glucose levels don’t rise too high….giving you a full 2 hours worth of its energy.
- Medium GI foods take around an hour.
- High GI foods are absorbed quickly – in 30 minutes or less, so that blood glucose spikes higher. More insulin is required when blood glucose rises. This may be an issue for people with diabetes whose insulin secretion tends to be sluggish. Other people, when confronted with a high glucose load, might oversecrete insulin, causing the blood sugar to drop too low. This is often called reactive hypoglycemia.
What Foods Are In Each Category?
- High glycemic index foods include breads, rice, and processed cereals…but also some fruits and vegetables like watermelon, bananas, and potatoes. Desserts and fluid replacement beverages like Gatorade and Powerade fit into this category too.
- Medium glycemic index foods consist of some fruits like berries, oranges, and grapes. Fruit juice and sodas are both in this category. Pasta, whole grain breads, and vegetables including sweet potatoes and carrots.
- Low glycemic index foods: most other fruits and vegetables not listed previously fall into the low glycemic index foods. Also, milk and yogurt. Beans, hummus, and quinoa. Nuts and nut butters. And, even treats like chocolate, popcorn, and ice cream.
For a more detailed list, go to glycemicindex.com
If you’re watching your glycemic index, please don’t just eat the low glycemic index foods and skip the others. First of all, you’ll be missing out on some very healthy foods. Secondly, avoiding those foods are totally unnecessary. The GI is not an exact science. Much of the glycemic response you’ll get from foods depends on 1) how much of that food you’re eating 2) what else you’re eating with it, and 3) specifics such as how the food was prepared, cooked, and so much more. And, that’s what I’ll be covering in part 2 of this series on the glycemic index.