Blood sugar and the glycemic index

The glycemic index is a way of measuring how much a given food can raise your blood glucose level. The glycemic index is a scale that measures against pure glucose, so if you’re trying to keep your blood sugar relatively low, foods that are low on the glycemic index are generally a good bet.

Eating food that’s high on the glycemic index doesn’t just raise blood sugar higher, though, it raises it faster, and it eventually drops faster, too. Spikes like this can lead to hyperglycemia, which can be dangerous if it’s left untreated. Foods that are lower on the glycemic index cause slower and more gradual rises and falls in blood sugar levels, which are easier on the body.

The glycemic index

The glycemic index is generally divided into three parts, with foods falling into the category of low, moderate, or high on the glycemic index.

Low: Foods that fall low on the glycemic index are measured to have a GI of 55 or less. Most whole fruits and vegetables fall into this category, as do less processed grains, nuts, low-fat dairy, and pasta.

Moderate: Foods that fall on the moderate section of the glycemic index scale score a GI of 56 to 69, and are generally on the starchier side – potatoes and sweet potatoes, corn, white rice, couscous, and even breakfast cereals that seem like they should be on the healthier side, like shredded mini wheats.
High: Foods with a GI of 70 or higher, like white bread, and white flour products like bagels, cakes donuts, waffles or crackers, or most breakfast cereals are considered high on the glycemic index, and can lead to abrupt rises and falls in blood sugar levels.

The best way to use the glycemic index, generally, is to swap out foods that are a part of your regular diet that fall into the high or moderate categories of the glycemic index, and use it to find equivalents you can trade those high GI foods for from the moderate or low part of the scale.

As with any other big change to the way you eat, it’s important to make sure that, as you change your diet, you’re still getting all the nutrients you need. If you have other dietary restrictions, like allergies or being vegan, it can be helpful to talk through your regular diet with your healthcare provider, to make sure that, if you start adapting your diet further to fall lower on the glycemic index, there aren’t any nutrients you’re missing out on that it might be good to supplement.

Sources

Mayo Clinic Staff. “Gestational Diabetes: Treatments and drugs.” MayoClinic. Mayo Foundation for Medical Education and Research, Apr 25 2014.
“Tips to control your blood sugar.” DiabeticLivingOnline. Meredith Corporation, 2016. Web.
Patrick J Skerrett. “Use glycemic index to help control blood sugar.” Harvard. Harvard Health Publications, Harvard University, Aug 2012. Web.