Starches are carbohydrates, and you should eat 45 to 65 percent of your total calories per day as carbohydrates, according to the Dietary Guidelines for Americans 2010. The total number of calories you need per day depends on your age, weight, height and activity level. Aim to eat carbohydrate sources of whole grains, fruits and vegetables. Corn, white and sweet potatoes, lima and dried beans, and peas are starchy vegetables because of their high carbohydrate concentration. Other vegetables, including beets, carrots, onion, cauliflower, broccoli, and leafy greens, are nonstarchy vegetables because they have insignificant amounts of carbohydrate. Both starchy and nonstarchy vegetables are healthy options, but nonstarchy, fibrous vegetables have more benefits, such as reducing the risk of heart disease.
The glycemic load of starchy vegetables is high because they contain simple sugars and are rapidly digested. Glycemic load is the amount of carbohydrate in a food multiplied by the glycemic index, which measures the dietary carbohydrate of a food and its ability to raise blood sugar levels compared to a different food, most commonly glucose. Nonstarchy vegetables have a low glycemic load. Foods with lower glycemic loads are associated with better blood sugar control and lower cholesterol levels.
Type 2 Diabetes
Nonstarchy vegetables are a great food for those with Type 2 diabetes because of their nutritional benefits. You can eat as many nonstarchy vegetables as desired without worrying about negative consequences and improve your hemoglobin A1C, which is a measure of how well diabetes is controlled. Starchy vegetables, however, can induce negative effects if eaten in excess with other starchy foods. Eating many starches, which all have high glycemic loads, can increase the risk for Type 2 diabetes, according to an article in the October 2007 issue of the "European Journal of Clinical Nutrition."
Aim to eat healthy amounts of starches and more nonstarchy vegetables to avoid elevated blood triglycerides. Eating too many starches can result in hypertriglyceridemia, elevated levels of blood triglycerides in the blood due to a trigger of the body to release large amounts of insulin. After eating a meal, absorption of food is complete within two hours. Eating too much starch can result in insulin prolonging its action, causing blood sugar levels to drop, sometimes below normal. As a result, the body thinks it is starving, which causes the secretion of hormones that release free fatty acids from fat cells. These fatty acids are packed into transport lipoproteins in the liver, causing blood triglycerides to rise.
Fiber, folate, potassium, flavonoids and antioxidants found in both starchy and nonstarchy vegetables have protective effects against heart disease. Risks of coronary heart disease and of ischemic stroke are significantly decreased due to these components. Nonstarchy vegetables provide greater protective effects due to their lower glycemic load and generally higher concentrations of nutrients. You should consume colorful vegetables, especially green, blue, purple, orange, red and yellow ones because they are heart-healthy and generally not starchy.
- European Journal of Clinical Nutrition: Dietary Carbohydrate: Relationship to Cardiovascular Disease and Disorders of Carbohydrate Metabolism
- Krause’s Food and Nutrition Therapy; L. Kathleen Mahan, et al.
- USDA: Dietary Guidelines for Americans, 2010