Using the Glycemic Index

Working with DVIF&G’s team of medical nutrition therapists,  our doctors help patients achieve a healthy weight to enhance their fertility. One of the tools that they use in nutrition counseling is the Glycemic Index. It’s a tool used to rank different types of carbohydrates, such as white rice, pasta, or cereal, according to their effect on blood sugar levels, also known as glucose levels. The higher the Glycemic Index rating, the faster that carbohydrate turns to sugar in your blood. The lower the Glycemic Index rating, the slower it turns to sugar in your blood. It’s important to remember that it measures not only how much the blood sugar level rises, but also how quickly.

A very important sugar of which most carbohydrates are comprised, glucose provides energy to the body’s cells after it has been carried to them in the bloodstream. It can be used immediately or stored for later use. When there’s too much glucose in the blood, high blood sugar occurs known as hyperglycemia. When there’s too little glucose in the blood, low blood sugar occurs known as hypoglycemia. Neither condition is recommended. The body works to keep these levels in balance. Use of the Glycemic Index can help achieve a glucose balance that’s right for a particular individual.

The DVIF&G team recommends choosing foods with a low GI, 55 or lower. Numbers between 55 and 69 are moderate, and anything over 70 is considered high. Foods that contain any amount of carbohydrates that have a low GI number include most vegetables, legumes, whole grain breads, and most fresh fruit. Foods with carbohydrates that have a high GI include white breads and rolls, pretzels, white pasta, white rice, and sweetened fruit juice.

The DVIF&G team recommends choosing foods low on the Glycemic Index for several reasons:

  • When you eat carbohydrates that rate low on the GI scale, you’ll have more energy.
  • When you eat carbohydrates that rate low on the GI scale, you’ll feel more satisfied with less food.
  • When you eat carbohydrates that rate low on the GI scale, you’ll experience no cravings.
  • When you eat carbohydrates that rate low on the GI scale, you’ll be less likely to overeat.

When planning meals and snacks, be sure to choose those complex carbohydrates that will give you more “Nutritional Bang for Your Buck.” Choose whole grains. Snack on vegetables and fresh fruit. Enjoy tossed green salads with a light olive oil vinaigrette. Start a meal with nutritious bean soups. You will feel better and be more satisfied while eating less.

It’s also important to note that the Glycemic Index should be used as a guide, not as a strict list of foods that are allowed and foods that are forbidden. Because the GI is an average, you need to be aware that the GI of a food can be highly individual. If you notice that one of the lower GI foods causes you to gain weight or creates cravings for sweets or more carbohydrates, then you know to leave that food out of your diet.

Be sure to control portion size. Even though a certain carbohydrate may be on the lower half of the index, larger helpings of that food can still rigger excessive insulin surges. When you start to use the Glycemic Index, consider one-half cup of a certain food to be a serving. Then see how that amount works for you over time.

The Limitations of the Glycemic Index

Our team of medical nutrition therapists at the Delaware Valley Institute of Fertility & Genetics (DVIF&G) in Marlton help patients make healthy lifestyle changes to prevent certain diseases, including obesity, type 2 diabetes and cardiovascular disease but primarily to treat infertility. Studies have shown that the role of diet and nutrition is very important not only in helping couples conceive, but also in helping them achieve a healthy pregnancy and birth. Recently, both the American College of Obstetricians and Gynecologists (ACOG) and the American Medical Association (AMA) have issued policy statements encouraging practicing OB/GYNs in particular, and primary care physicians (PCPs) in general, to address preconception health issues in women of reproductive age.

One of the tools that they may reference in nutrition counseling is the Glycemic Index (GI). The GI is a tool used to rank different types of carbohydrates, such as white rice, pasta, or cereal, according to their effect on blood sugar levels, also known as glucose levels. The higher the GI rating, the faster that carbohydrate turns to sugar in your blood. The lower the GI rating, the slower it turns to sugar in your blood. The body works to keep these levels in balance. Use of the GI can help achieve a glucose balance that’s right for a particular individual.

But there are limitations to using the GI as the primary guide to nutritional intake. It should be used as a reference tool, not as a strict list of foods that are allowed and foods that are forbidden. Because the GI is an average, the GI of a food can be highly individual. For example, just because a GI of a particular food is not supposed to raise blood sugar levels, that doesn’t mean that it won’t in certain individuals.

It’s also crucial to control portion size. Even though a certain carbohydrate may be on the lower half of the index, larger helpings of that food can still trigger excessive insulin surges and extra calories causing weight gain. The same applies for a high GI. If smaller portions are eaten, insulin surges and glucose levels are minimized. Also, when carbohydrates are eaten along with other foods, the blood glucose response and GI will vary, depending upon the amount of carbohydrate, protein, and fat in the mixed meal.

A registered dietitian (RD) can help develop a personalized meal plan for an individual, one that achieves the optimum balance of carbohydrates, protein, fat, and vitamins and minerals. Instead of solely focusing on GI ratings, the RD helps the person control portion sizes, total carbohydrates, and fat intake to achieve a healthy weight.

We have helped hundreds of women adopt a healthy lifestyle. Since nutritional adjustments require changes in well entrenched habits, this can be associated with additional stress that can undermine the effort in developing a  new healthy lifestyle. Therefore, low-impact exercise, eating right, and meditation, or other stress reduction techniques are included. The GI offers insight to registered dietitians in planning nutritious meals for their patients, but it’s only one of many reference tools used by us to create meal plans that deliver healthful benefits.

By Karla D. Boyce, RD, LDN, CDE