Questioning the Benefits of Carb-Counting
Diabetic patients are often told to count carbs in order to control their blood sugar levels, but do other methods work just as well?
Counting carbohydrates has long been considered the tried-and-true method for helping diabetics control their blood sugar levels. Yet, a new meta-analysis suggests its effectiveness is limited.
Five of seven studies found only modest improvements in blood sugar levels among carb-counters, when reserachers analyzed interventions longer than three months that compared carbohydrate counting with general or alternate dietary advice in adults and children with type 1 diabetes, according to research published in The Lancet Diabetes & Endocrinology (Oct. 31, 2013). However, the other two studies reviewed found carb counting no more effective than alternative methods.
Based on their results, it’s possible that other methods of matching insulin with food are not being studied because of the belief that carbohydrate counting is a well-founded, evidence-based therapy, stated the study’s authors.
Given the doubts raised by the meta-analysis, should diabetic patients stick with carb-counting? Cleveland Clinic registered dietitian and certified diabetes educator Andrea Dunn, RD, LD, CDE, says yes.
“I think the major argument is the fact that studies are limited and could be better designed,” says Dunn. The relationship between carbohydrate intake and blood sugar levels, however, is well established.
“Carbohydrate-containing foods and beverages are the main determinants of the blood sugar level after eating,” Dunn says. “So knowledge of what foods contain carbohydrates is needed.”
Dunn encourages diabetic patients to be mindful of the quality, and not just the quantity, of their carbohydrate intake. “We generally encourage nutrient-dense foods when choosing carbohydrates. Instead of processed foods with added fat, sugar, and salt, we promote choosing whole grains, legumes, vegetables, fruit, and low-fat dairy,” she says.
While Dunn prescribes carb-counting for many diabetic patients, she admits it won’t work for everyone. “The other thing to keep in mind is that if a person is on a medication that causes the blood sugar to go low, it is best to be on a consistent carbohydrate style of eating,” she says. “Skipping carbohydrates while on these medications can cause blood sugars to go below goal range, which is not safe.”
Julia Zumpano, RD, LD, a registered dietitian at Cleveland Clinic, says she believes in the value of carb-counting as well. But she also stresses the importance of the glycemic index, a measure of how quickly blood sugar levels rise after eating a particular food. Not all carbohydrates are created equal, and varying glycemic loads do make a difference for people with diabetes.
“They mentioned glycemic index in the study as being important,” says Zumpano. “I tend to encourage carb choices that have a lower glycemic index—such as dried beans, legumes, quinoa, brown rice, barley, and steel cut oats—as the main sources of carbs, even when I provide carb-controlled meal plans.”
On that point, the researchers agree: The study suggests that eating a low-glycemic diet, rather than simply counting carbs, may lead to better patient outcomes.