4 reasons why the glycemic index is outdated | livestrong.com (2023)

If you are living with diabetes, counting carbohydrates is a smarter strategy than focusing on the glycemic index of foods.

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The glycemic index has long been used as a tool to assess a food's effect on blood sugar levels, but it is not without its flaws.

We asked registered dietitians and an endocrinologist to explain how useful the glycemic index (GI) is for people trying to control their blood sugar and what to focus on.

"The glycemic index is a metric that measures how certain foods raise blood sugar levels," he explains.Christine Russell, RD, CDCES, Registered Dietitian and Diabetes Care Instructor and Education Specialist with Nutrition Counseling Companynurture.

Developed by doctors in 1981, the GI attempts to quantify the effects of food on blood sugar levels compared to sugar. Glucose (also known as sugar) has a GI of 100. Other foods are numbered from 0 to 100, with the number indicating how much a food tends to raise blood sugar levels compared to glucose. This is how it looks in practice:

The reasoning is that "foods with a high glycemic index would be less ideal for people with diabetes because they are more likely to cause spikes and crashes in blood sugar, which is not only unfortunate from the point of view that it can do make the person feel uncomfortable, but they do." It's also hard to figure out the right dosage for insulin medications and treatments," she says.Maryann Walsh, RD, CDE, registered nutritionist, certified diabetes educator, and founder of the Walsh Nutrition Clinic.

On the other hand, "low-glycemic foods would be better because they cause fewer spikes and dips in blood sugar," says Walsh.

Understanding how certain foods affect blood sugar levels is certainly helpful, whether or not you've been diagnosed with diabetes. But GI misses out on some key factors in this equation.

Here are four reasons why the GI isn't the most useful tool when it comes to choosing blood sugar-friendly foods.

First things first: "The glycemic index doesn't take into account how much we actually consume at one time," Russell says.

That is, glycemic index values ​​were assigned to foods based on a serving of that food containing 50 grams of carbohydrate. This serving size makes sense for some foods. For example, you would need to eat about 1 cup of cooked white rice (which has a GI of about 73) to get 50 grams of carbs from that meal. This is an absolutely realistic portion of rice.

However, you would need to eat about 7 whole cups of watermelon (which has a GI of about 76) to get 50 grams of carbs from the fruit. Most people don't eat that much watermelon at one time, so the fruit's high GI may not be that significant.

"Serving sizes give a more accurate picture of how a given food affects blood sugar during a meal," Russell says. This is why the “glycemic load” was created. Unlike the GI, the glycemic load is responsible for both the glycemic index ‌mi‌ the portion actually consumed.

Take this watermelon for example. fallsalternative‌ on the glycemic index, but ‌low‌ in terms of glycemic load (which is only 8) once a standard serving size is considered, e.g.Oregon State University.

Several variables can alter the glycemic index of a food.

"Certain preparation methods or even natural processes like fruit ripening can change the GI of a food," Walsh explains. “For example, the riper the plantain, the higher its GI. In terms of preparation methods, rice is an example of a food that has a higher GI when freshly prepared, but a lower GI after cooling and then reheating. "

This change has to do with the formation ofresistant starchon carbs cooked and then chilled.

One of the shortcomings of the GI is that it focuses on a single macronutrient, carbohydrates, rather than the entire nutritional profile of a meal.

For example, we often eat carbohydrates like rice or potatoes along with other foods, not entirely on their own. Combining starches with other foods, such as chicken for lean protein and broccoli for fiber, slows down how quickly those starches are digested, in turn raising blood sugar levels.

"Eating carbohydrates alone is more likely to raise blood sugar faster and more dramatically than eating carbohydrates with a lean protein orhealthy source of fat', dice Walsh.

While GI advocates encourage people to calculate the glycemic index of foods based on the specific value of each component, the process can be tedious and potentially flawed. In fact, estimates of the glycemic index of whole foods overestimated their values ​​by up to 50% compared to first-hand measurements of the actual GI of meals in a small October 2011 study.‌american journal of clinical nutrition‌.

Focusing solely on the GI of a food means that other essential nutrients for diabetes may be overlooked.

"High glycemic index [carbohydrates]like whole wheat bread and oatmeal contain fiber," Russell says. "Fiber acts as a physical barrier and slows the release of sugar into the bloodstream."

The problem also turns to the other side. "Not all low GI foods are ideal choices and can actually be low in nutrients and high in saturated fat," Russell explains. “For example, French fries have a lower GI than oatmeal and sweet potatoes; However, oats and sweet potatoes contain more nutrients, less fat, and more fiber."

"The utility of the GI is clearly very subjective and nuanced, like most other aspects of nutritional science," says Walsh. "Two foods can [both] have a high GI, but they can differ in terms of overall nutritional benefit to the person when we consider [other nutrients such as] vitamins and minerals."

These tips may be more helpful in optimizing your stats.

If you want to make your diet more compatible with your blood sugar, start by remembering your daily added sugar goal.

oAmerican Heart Associationrecommends limiting added sugars to no more than 6% of calories per day, which works out to 24-35 grams per day, depending on how many calories you eat.

"This is also a good rule of thumb for people with diabetes," says Walsh.

Check Nutrition Facts labels for the amount of added sugar in commonly sweetened foods, such as soft drinks, yogurt, breakfast cereals, and packaged snacks. Keep in mind that the amount of added sugar listed on the label is for a single serving of the food. So you need to multiply that amount of added sugar if you want to eat more than one serving.

“My general advice for those looking to improve their blood sugar is… combine simple carbohydrates like bread or pasta with something that contains protein, like meat or cheese.delay a rise in blood sugarsaid Dr. Adimoolam.

Rapid spikes and dips in blood sugar levels can trigger hunger, which can lead to increases in caloric intake that may not align with weight management or carbohydrate intake goals, he adds.

Here are some pairing examples.carbohydrate foodswith lean protein and healthy fats to mitigate post-meal blood sugar spikes:

Glycemic index values ​​do not always match the fiber content of a food, andeat enough fiberit is an essential part of blood sugar control. This is because non-digestible carbohydrates help slow the rate at which sugar enters the bloodstream, preventing spikes in glucose levels.

Whether diagnosed with diabetes or not, all adults should aim for 14 grams of fiber for every 1,000 calories consumed daily (with fiber from whole food sources like vegetables, fruits, whole grains, and beans) according to the Dietary Guidelines. 2020-2025. for the americans

A moderate carbohydrate diet (‌NO‌ a bass orno carb diet) is the leading nutritional intervention for blood sugar control, Russell says.

Although the glycemic index can be a useful tool when used in combination withcarb countKnowing how to eat the right amount and type of carbohydrates for your body and your blood sugar is helpful.

Get support from board-level health professionals like board-level endocrinologists and registered dietitians who can teach you carb counting and optimal eating habits for blood sugar control. Chances are, your personalized plan will go beyond the glycemic index.