A dietary tool called the glycemic index, or GI, measures how quickly a carbohydrate-containing food is digested and converted into glucose in the body. Maintaining a steady level of glucose in your bloodstream instead of riding a roller coaster of energy peaks and troughs can have positive effects on your health, including improved weight management and reduced risk of chronic disease. Slow digesting carbs that rank under 55 on the GI are sometimes called "slow" carbs because they digest more slowly.
Vegetables and Fruits
Most vegetables are low GI foods, including artichokes, asparagus, broccoli, cabbage, cauliflower, celery, eggplant, all types of greens, okra, peppers, squash and zucchini. Examples of slow carbs among the starchy vegetables are peas, carrots, parsnips and yams are all slow digesting. Fruits tend to be higher in natural sugars than vegetables and so they are digested and absorbed more quickly by the body. Still, a number of fruits are considered slow carbs, including apples, oranges, peaches, pears, plums, nectarines and grapefruit.
Beans and Legumes
Beans and legumes make good choices when you're looking for slow digesting carbs. Those with a GI under 55 include baked beans, black-eyed peas, black beans, chickpeas, kidney beans, navy beans, lentils, soybeans and peanuts. The added advantage of these foods is that they are rich sources of plant protein if you are trying to reduce your intake of animal protein.
Types of Grains
In general, whole-grains digest more slowly than highly refined grains like white bread. The slowest-digesting grains include 100 percent stone-ground whole wheat or pumpernickel bread, wheat and corn tortillas, quinoa, brown rice, rolled or steel-cut oatmeal, oat bran, barley and bulgur. Of these, barley and oats have the lowest GI values, according to Grains and Legumes Nutrition Council.
Dairy and Non-dairy Alternatives
You may not think of dairy products as carbs, but these foods supply natural sugar in the form of lactose. Some slow-digesting dairy foods include skim and full-fat milk; cheeses such as Cheddar, mozzarella and cottage; and yogurt. Non-dairy alternatives like almond and soy milk are also considered as slow burning carbs, but rice milk is not.
Nuts and Seeds
With their high fat, high protein and low carbohydrate content, nuts and seeds are slow digesting foods. For example, walnuts, almonds, pistachios, pine nuts, hazelnuts and cashews all rank under 25 on the GI, while sesame, amaranth, squash, sunflower and sprouted seeds are under 35. Peanut butter is a slow digesting carb, as are unsweetened pastes and butters made from low-GI nuts.
Benefits of Low Glycemic Foods
LDL cholesterol is associated with the risk of stroke and heart disease, a major cause of mortality in diabetics. Low-glycemic foods have been shown to reduce total LDL cholesterol. A study systematically reviewed 28 trials on the effects of low GI diets on blood lipids. Findings published in Nutrition, Metabolism, and Cardiovascular Disease showed consistent evidence that low GI foods reduce total LDL-cholesterol with no effect on HDL-cholesterol.
A condition known as fetal macrosomia causes a newborn to be born significantly larger than average. It happens in woman who develop high blood sugar levels during pregnancy, even if they are not diabetic. A study, published in the journal Medicine in 2016, found that a low-glycemic diet reduced the risk of macrosomia by a significant amount.
- The Glycemic Index: About Glycemic Index
- Optimalfoods.org: Low Glycemic Foods
- The Dr. Oz Show: Low Glycemic Vegetable List
- Harvard Medical School: Glycemic Index and Glycemic Load for 100+ Foods
- Vegetarian Resource Group: Protein in the Vegan Diet
- PubMed.gov: Effects of Low Glycemic Index Diets on Gestational Diabetes Mellitus: A Meta-Analysis of Randomized Controlled Clinical Trials. Wei J1, Heng W, Gao J.
- PubMed.gov: Low Glycaemic Index Diets and Blood Lipids: A Systematic Review and Meta-analysis of Randomised Controlled Trials.
- University of Sydney: Search for Glycemic Index