Foods that have a low to moderate glycemic index rating help prevent blood sugar spikes and keep glucose levels steady. These foods are usually high in fiber and low in simple carbohydrates like refined sugar. Build your diet around fruits and vegetables, lean meats and seafood, whole grains and low-fat dairy to keep blood sugar levels low. Also include specific foods within these categories, such as onions and soybeans, that have been scientifically shown to lower blood sugar. Always consult your doctor about what foods you should eat to manage your blood sugar. The Cleveland Clinic recommends contacting your doctor if your blood sugar is over 180 milligrams per deciliter for more than seven days or if two consecutive readings are over 300 milligrams per deciliter .
The glycemic index is a measure of how much a food will raise your blood sugar after eating. A food with a GI score of 70 or more -- white bread, russet potatoes and white rice -- is high on the scale and likely to spike your blood sugar. Foods with a score of 56 to 69 are moderate, and foods with a score below 55 are low-GI foods. Medium-GI foods include quick oats, whole-wheat or rye pita bread and brown and wild rice, while low-GI foods include most fruits and all nonstarchy vegetables such as lettuce, green beans, brussels sprouts and tomatoes; starchy vegetables like corn, sweet potato and beans; 100 percent whole-wheat bread; and oatmeal and muesli.
Fiber is the part of plant foods that your body can't digest. It passes through your digestive tract largely unchanged, but it slows digestion and the absorption of sugar into the bloodstream and helps to keep blood sugar steady. The foods highest in fiber are cauliflower and broccoli, cabbage, berries, leafy greens, celery, squash, beans, mushrooms and lentils. Whole grains are also good sources of fiber.
Protein and fat don't have much of an effect on your blood sugar levels; only carbohydrates have a noticeable effect. Proteins and fats are digested more slowly than carbohydrates, however, and when eaten with medium- or high-GI carb, protein and fat can help to slow the absorption of sugar into the bloodstream and blunt the blood-sugar-raising effects. If you're going to eat a medium- or high-GI carb, pair it with a serving of lean protein such as white-meat chicken or tofu and a serving of healthy fat, such as a little olive oil or an ounce of walnuts.
Certain foods have been studied for their blood-sugar-lowering effects. Results of a study presented at the Endocrine Society's 97th annual meeting showed that onion bulb extract significantly lowered blood sugar in diabetic rats. This has not yet been tested in humans. Another study published in Nutrition Research and Practice in September 2008 found that supplementation with roasted soybean powder three times daily significantly reduced both fasting glucose and post-meal glucose. Leafy greens are another excellent choice. A study published in Diabetes Care in December 2004 found that over a 10-year period, women who ate a diet rich in leafy greens were the least likely to develop type-2 diabetes.
- American Diabetes Association: Glycemic Index and Diabetes
- Ask Dr. Sears: Glycemic Index
- HealthAliciousNess.com: Top 10 Foods Highest in Fiber
- Joslin Diabetes Center: How Does Fiber Affect Blood Glucose Levels?
- Precision Nutrition: All About Carbohydrates
- EurekAlert: Onion Extract May Improve High Blood Sugar and Cholesterol
- Nutrition Research and Practice: Effects of Soybean Supplementation on Blood Glucose, Plasma Lipid Levels, and Erythrocyte Antioxidant Enzyme Activity in Type 2 Diabetes Mellitus Patients
- Diabetes Care: A Prospective Study of Fruit and Vegetable Intake and the Risk of Type 2 Diabetes in Women
- Cleveland Clinic: Hyperglycemia (High Blood Sugar)