The Glycemic Index: A Guide for Meal Planning
The glycemic index (GI) is a helpful meal-planning tool for those needing to manage their blood glucose levels.
The GI ranks foods containing carbohydrates – using a scale of 0 to 100 – according to their effect on blood sugar. Foods with a higher index ranking are those the body digests quickly, causing spikes in blood sugar. Foods with a low GI ranking are digested more slowly, elevating blood glucose gradually.
The goal is to consume mostly low and some medium GI foods, and to offset the effect of high GI foods by combining them with low ones (a high GI carb mixed with a low GI carb equals a low to medium GI carb).
55 or Less: Low GI Foods
- Stone-ground whole grains, rolled or steel-cut oats, oat bran, muesli
- Pasta, barely, bulgar, converted rice
- Sweet potato, yam, lima/butter beans, legumes, lentils, peas, corn
- Many fruits, non-starchy vegetables and carrots
56 to 69: Medium GI Foods
- Whole wheat, rye, pita bread, quick oats
- Brown, wild, or basmati rice, couscous
- Bananas, raisins
70 or More: High GI Foods
- White bread, bagels, processed cereals (e.g., corn flakes, instant oatmeal)
- Shortgrain white rice, macaroni and cheese from a mix, rice pasta
- Pumpkin, russet potato; melons and pineapple
- Rice cakes, pretzels, popcorn, saltine crackers
Six GI Meal-Planning Guidelines
Unless you are following a strict GI diet, you only need to keep some overall GI principles in mind to use the index as a guide.
- A key word to remember is balance. You can balance-out the effects of a high GI food by eating it with low GI foods. This is important to know since some desirable nutritious foods have a high GI. Conversely, some low GI foods have little nutritional value and should be eaten sparingly, or balanced with more nutritious selections.
- Choose whole, unprocessed foods most of the time. Foods that are intact or whole go through our digestive tract more slowly, elevating our blood sugar more evenly, and keeping us satisfied longer. When possible choose stone-ground, sprouted, or cracked-wheat breads and crackers (grain kernels will be visible). Whole fruits are preferable to juice.
- High fiber foods generally have a lower GI ranking. Fiber-full foods include nuts, beans, whole grain breads and pasta, and high-fiber cereals.
- Pair carbohydrates with protein. The stomach empties more slowly when we give it protein to digest. By adding chicken to a pasta dish or putting peanut butter on toast, we can slow our digestion and lower the GI value of the meal.
- Remember the healthy fats. Like protein, fat molecules digest slowly. Dipping bread in olive oil, and tossing walnuts, almonds, or avocado on a salad will reduce the food’s GI number and make the dish more satisfying as well.
- Timing makes a difference. The longer a fruit or vegetable is stored – the riper it is – the higher its GI. Also, cooking food longer makes food softer and may raise the GI. Pasta, for instance, has a lower number when served al dente.
The International Diabetes Federation website (idf.org) has an excellent glycemic-index reference wheel. You can view the interactive wheel online or send for a paper copy.