Diabetic Diet: Is Determining Glycemic Load Better Than Counting Carbs?

To count carbs or discount them ‒ the debate continues. Being type 2 insulin dependent, I’m trying to make sense of the differing conclusions of two studies that have been published recently. It’s hard to say what these studies really show ‒ it can get confusing with all the information out there ‒ especially when pilaf (pilao) is on Sunday’s lunch menu!

Dr. Andrea Laurenzi of San Raffaele Vita-Salute University in Milan suggests that diabetes patients may benefit from counting the number of carbohydrates in their diet. In a small study ‒ published online in the America Diabetes Association journal Diabetes Care ‒ the Milan researchers looked at 61 adults on insulin pump therapy and found that those who learned to count carbs had a small reduction in weight and waist size after 6 months. Additionally, they reported gains in quality of life and an improvement in blood sugar levels.

On the other hand, Jiansong Bao at the University of Sydney in Australia, says the number of carbs alone might not be the best way to go. Writing in the American Journal of Clinical Nutrition, he feels that how many carbs you eat might be less important for your blood sugar than your food's glycemic load, a measure that also takes into account how quickly you absorb those carbs.

Dr. Sanjeev Mehta, of the Joslin Diabetes Center and Harvard Medical School in Boston says while Laurenzi’s findings do not prove that carb counting is the answer for people with type 1 diabetes, it is widely recommended that people on insulin try to estimate the carbohydrate content of their meals to help calculate their insulin doses. Indeed, a few other studies too have suggested that carbohydrate counting can help people with type 1 diabetes control their blood sugar levels.

There are books and online resources available for people who are interested in learning how to count carbs. However, some people have difficulty learning or sticking with the method, Mehta noted, and benefit from help from a professional, such as a dietitian or certified diabetes educator.

Mayo Clinic nutritionist Katherine Zeratsky, R.D., L.D. explains counting carbohydrates is a method for controlling the amount of carbohydrates you eat at meals and snacks. This is because they have the greatest impact on your blood sugar. Eating consistent amounts of carbohydrates every day helps you control your blood glucose level.

But carbohydrates aren't the only dietary consideration when you have diabetes. You need to also limit fat and cholesterol and control the number of calories you consume. The best way to do this is to control portion sizes, she says.

“Eating a healthy diet helps you control your diabetes and reduces your risk of diabetes-related conditions, such as heart disease and stroke. So, just because a food contains no carbohydrates doesn't mean that you can eat it in unlimited amounts,” she cautions.

However, Bao claims the so-called glycemic load of a food, which also takes into account how quickly it makes the blood sugar rise, might work better. Foods with soluble fiber, such as apples and rolled oats, typically have a low glycemic index, one of the contributors to glycemic load. Foods with a low glycemic index cause the blood sugar to rise slowly, and so put little pressure on the pancreas to produce insulin.

The glycemic load is calculated by multiplying the amount of carbs in grams per serving by the food's glycemic index divided by 100. (The glycemic index for a variety of foods can be found here.)

The Sydney researchers say their findings also suggest that eating foods with high glycemic loads could be linked to chronic disease like type 2 diabetes ‒ which does not require insulin injections ‒ and heart disease by raising blood sugar and insulin levels.

The researchers took finger-prick blood samples from 10 healthy young people who ate a total of 120 different types of food ‒ all with the same calorie content. They also had two groups of volunteers eat meals with various staples from the Western diet, such as cereal, bread, eggs and steak. And the glycemic load repeatedly trumped the carb count in predicting the blood sugar and insulin rise after a meal.

A Reuters report quotes Dr. Edward J. Boyko ‒ a diabetes expert at the University of Washington in Seattle who wasn't involved in the Sydney study ‒ saying it wasn't certain the findings would hold up in people who aren't completely healthy, adding, long-term effects and other nutrients in the food might also be important for disease risk.

"It would just be speculation whether a dietary change like this would help people with type 2 diabetes." The most important problem, Boyko points out, remains pure and simple overeating. "The excess weight is the main thing we ought to focus on…The simplest message would be, eat less."

Promoting Self-Management is Essential to Properly Treat Type 2 Diabetes

One of the most important aspects of diabetes management is educating the patient to manage their condition themselves. This is known as Diabetes Self-Management Education, better known by its acronym DSME. It has been demonstrated by many studies that education works.

DSME is defined as the ongoing process of facilitating the knowledge, skill and ability necessary for effective self-management and is guided by evidence-based standards. Patients with diabetes who do not receive DSME are found to be four times more likely to develop a major complication of diabetes and incur higher diabetes-related hospital costs.

I support the concept of DSME, given the fact that many family doctors do not have enough knowledge to effectively advise diabetes patients (see my earlier post ‘Why most doctors are clueless about treating diabetes’) and visits to a specialist involve long waiting periods and longer commutes.

In this interesting interview conducted by Endocrine Today, Linda Siminerio, RN, PhD, CDE, director of the University of Pittsburgh Diabetes Institute, and associate professor at the University of Pittsburgh School of Medicine and the School of Nursing answers many questions regarding DSME.

How can physicians effectively educate patients who currently have type 2 diabetes?
I think it is always helpful when physicians have access to additional resources to support team-based care. For example, referral to dietitians and diabetes education programs can be a powerful adjunct for comprehensive, quality care given the limited time they have available to spend with their patients. I have been involved in many studies and national surveys on referral practices, and we found that physicians often do not refer patients to these programs.

How can physicians effectively educate patients who are at risk for developing type 2 diabetes?
It is important for physicians to know what lifestyle intervention resources that address weight reduction and physical activity are available in their communities so that they can refer patients appropriately. Local YMCAs that offer lifestyle programs can be a valuable resource for physicians and patients. For example, in Indiana, some YMCAs have adapted the Diabetes Prevention Program (DPP) into a 16-week diabetes reduction program in the community setting. In Pittsburgh, the Diabetes Prevention Resource Center offers a 12–week Group Lifestyle Balance (GLB) program adapted from the DPP that is offered at community sites and in primary care practices. Physicians and practice staff should explore their respective communities to find community-friendly resources for their patients at risk for chronic disease.

What are your recommendations for creating collaboration between physicians and educators?
Physicians can refer their patients to the American Diabetes Association Web site to learn about community-based, recognized self-management education programs. Additionally, the American Association of Diabetes Educators Web site provides a variety of education materials that can be downloaded.

Even if patients obtain referrals from their physicians to participate in a program, they may not attend. I recommend that educators be integrated in the practice so that the educator becomes a part of the practice team. Educators and physicians should work together. Other support mechanisms are available in communities, but they are not always used. Primary care physicians should work with others in the community, such as local pharmacists, to effectively educate patients.

How can physicians promote diabetes self-management?
Diabetes self-management education (DSME) should always be considered as part of the treatment plan, even if a patient is reported to have excellent metabolic control. Attention to self-care behaviors and psychosocial needs are equally as important as metabolic outcomes when managing a burdensome, chronic disease like diabetes. Active listening, providing accurate information and building a patient’s confidence are all important tools used in diabetes education. It is essential that physicians and everyone on the diabetes care team work together to support patient self-management by developing patient-centered goals that will be more likely to be achieved.

How do you determine the best treatment option for patients?
Every patient and situation is individual. Thus, it is important for everyone on the diabetes care team to take time to listen to the patient’s needs and desires. The physician, along with the team, should provide patients with the necessary information to build a realistic care plan. Patients need to be informed so they can make informed decisions about their own care.

Do patients who have received this sort of patient-centered care have better results in the long run versus patients who may not receive ongoing support?
Research shows that diabetes self-management is an important component of diabetes care and has an impressive effect on HbA1c levels. In a meta-analysis, diabetes education was reported to reduce HbA1c by 0.76%. Since a 1% decrease in HbA1c is associated with a dramatic reduction in myocardial infarctions, micro-vascular disease and death, a 0.76% reduction can be considered an enormous benefit. Further, duration of contact time between a patient and an educator is the only significant predictor of the DSME effect. This suggests that DSME alone is not sufficient to maintain improved behaviors and that sustained improvements require contact and follow up.

We also know that if education is not sustained or supported, then HbA1c levels go back up. So, we need to continue to explore opportunities for continued support. Community-based programs, like wellness programs, YMCAs, churches and senior centers are potential forums for community friendly self-management support systems.