In the body, all carbohydrate-based foods—such as sugar, grains, beans, vegetables, and fruit—convert primarily to glucose, or “blood sugar.” But different foods break down to blood sugar at very different rates. For example, sugary or starchy foods, such as white bread and pasta, table sugar, and very sweet fruits like bananas and pineapple, convert to glucose quickly and raise your blood sugar rapidly. Whole grains, beans, and non-starchy vegetables such as broccoli or green beans break down more slowly and therefore glucose gets into your bloodstream at a slower rate.
What is the Glycemic Index?
The glycemic index (GI) is a scale that rates how quickly a food raises your blood sugar level after eating it. The scale ranges from 0 to 100, with lower scores indicating foods that convert to blood sugar slowly. Higher scores indicate foods that become glucose in your blood quickly.
Generally speaking, the higher a food ranks on the index, the greater its effect on spiking your blood sugar level. High-glycemic foods eaten occasionally will spike blood sugar levels and lead to energy crashes – not a fun sensation but most people aren’t bothered too much by this if it happens infrequently.
The real problem is when someone’s daily diet is made up of too many high-glycemic foods. Over time, this kind of diet causes insulin resistance, high triglycerides, pre-diabetes, and eventually obesity and type 2 diabetes.
Sugar and Starch
While many people instinctively understand that sugary foods such as candy and soda have high GI values, a less obvious cause of high GI scores is starch. That is, foods such as pasta, bread, bagels, breakfast cereal, pretzels, rice, potatoes. All of these contain high amounts of starch and tend to convert to blood sugar rapidly, causing energy spikes and crashes.
On the other hand, foods that contain little or no starch, such as meat, fish, nuts, cheese, fats, and non-starchy vegetables (leafy greens, peppers, cucumber, green beans, tomato, broccoli, cauliflower, asparagus, etc.) are all “low glycemic” and a perfect for anyone looking to maintain balanced energy.
Of course, most people do not want—nor need—to avoid starch altogether. Fortunately for them, it’s easy to get a sense for which starchy foods rank highest on the glycemic index. They’re usually the ones that are highly refined.
Almost always, the more processed or refined a starch is, the higher its value on the glycemic index—for example, with white wheat flour, corn flour or white rice flour all have a high GI. This is very important to know for people trying to avoid gluten along with watching their sugar intake. Most gluten-free products contain highly refined non-wheat grain flours that have very high GI values.
Anyone who’s ever eaten a stack of pancakes made with white flour drizzled with sugary syrup knows precisely the energy crash of a highly refined, high-glycemic meal!
A Step Further: The Glycemic Load
While glycemic index tells us how quickly a food’s carbohydrates become blood sugar, it doesn’t reveal anything about the amount of carbohydrates in a typical serving of the food. For example, a whole bagel and a slice of watermelon both have a high GI value, but the bagel has a lot more carbohydrates. And all those carbs are going to have a more drastic effect on your blood sugar than the much fewer carbs in the watermelon—even though the carbs in each food convert to glucose at the same pace.
To reflect the carbohydrate amounts in typical portions of different foods, scientists created the “glycemic load” (GL). This basically shows the glycemic index for a food weighted by how many carbs are in a typical serving of that food.
Think about a whole baked potato versus half a baked potato: they have the same glycemic index, but the whole potato has twice the amount of carbohydrates, so its glycemic load is twice as much. In short, the glycemic load gives us a better idea of how foods affect blood sugar based on the typical amounts usually consumed.
Now I can hardly blame anyone if your eyes are glazing over at this point! If all of this GI and GL stuff is a bit too complicated, just remember these few basic rules:
Tips for Balancing Blood Sugar
Foods low in starch and sugar will have a minimal effect on your blood sugar. They include meat, eggs, nuts, fats, whole-fat dairy products, non-starchy vegetables. To maintain good energy, make them the foundation of your diet.
- When it comes to starchy foods (grains, beans, root vegetables), choose whole, fresh foods over processed or anything in a package. For example, cooked brown rice instead of a rice cake; steamed red skin potatoes instead of boxed mashed potatoes, etc.
- Focus on eating organic vegetables especially dark leafy green veggies.
- For grain foods, the more refined they are, the higher their glycemic index. So choose sprouted-grain bread over white bread, or brown-rice pasta over white-rice pasta. Keep grains (yes, including pasta) to a minimum in your total daily food intake.
- Think about portion sizes. Instead of a bowl of pasta, cut back to one cup or less.
- Some fruits like berries or apples have much less sugar (and therefore a much lower glycemic effect) than others like bananas, pineapple, mango.
- Fiber, fat, and protein slow the absorption of carbohydrates. So if you’re going to have a high-glycemic food, eat it after you’ve eaten these foods. For example, have a piece of fruit after a meal of chicken salad on sprouted wheat bread or dark chocolate after a stir fry of beef and broccoli.
Good luck with your new focus on low-glycemic eating! You’ll be amazed at how much better you’ll feel with even small, consistent changes to your diet.
Wishing you health and happiness!
Note: This information is provided as a resource and for educational purposes only. These recommendations are not intended as a substitute for consulting a physician or licensed healthcare practitioner. Individuals dealing with a serious or chronic health issue should consult with your doctor before beginning a nutritional program, taking supplements, discontinuing medications or eliminating foods from your daily diet. This information is not intended to replace medical advice from your doctor or to diagnose any health condition.