You Ask, I Answer: The Glycemic Index

What's your take on the glycemic index as a way to monitor "good" and "bad" foods?
-- Anonymous

Thirty years after it was first researched and introduced to mainstream nutrition, the glycemic index is making a comeback.

The glycemix index (GI) is a ranking that lists foods based on their effect on our blood sugar levels. Foods that spike up our blood sugar following consumption are ranked higher, while those that help maintain blood glucose levels receive a lower number.

Many low-carbers constantly refer to the GI, and will make statements like, “I don’t eat potatoes. They’re way up there on the glycemic index!”

Oh, the horror! If anyone ever tells you that, your nutrition BS alarms should go off.

Yes, it is true that foods largely composed of carbohydrates (especially refined ones) will raise our blood sugar more than those that mostly consist of fats and/or protein. That doesn’t necessarily make them less healthy, though.

For instance, according to the glycemic index, a croissant, ketchup, and ice cream are a better choice than cooked carrots. Thus, this tool does not take into account that ice cream and croissants have high levels of cholesterol-raising saturated fat and not a trace of fiber, ketchup is a high-sodium condiment, and cooked carrots offer a wealth of nutrients.

Additionally, I’m of the thought that the glycemic index oversimplifies foods. For instance, a baked potato scores high on this chart because the assumption is that you are eating it by itself. Have it as a side dish to accompany any protein (whether animal or vegetable), and the glycemic index of that potato becomes lower!

Similarly, cooking methods affect foods’ GI numbers. Pasta scores lower when al dente, and potatoes result in a lower number if they are refrigerated prior to being eaten.

Remember, when it comes to weight management, the main thing you truly need to keep tabs on is your caloric intake. Three thousand calories of food will make you gain weight, whether they come from lettuce leaves or ice cream (obviously, because lettuce leaves offer practically no calories, you would need to eat a LOT of them to even get 100 calories).

Although the glycemic index is definitely helpful for people living with diabetes (who need to closely monitor their blood sugar levels throughout the day), I don't consider it an effective weight management tool for the average person.