Your blood glucose levels are regulated by two hormones: glucagon and insulin. Glucagon helps elevate your blood glucose levels when they get too low by releasing excess sugar stored in your liver into your bloodstream. In contrast, insulin helps lower your blood glucose levels when they get too high. Sweet potatoes contain blood glucose-raising carbohydrates, and therefore, consuming the starchy vegetable will trigger your body’s production of insulin.
Carbohydrates and Sweet Potatoes
Foods that contain carbohydrates, such as sweet potatoes, affect your blood glucose levels. Carbohydrates include sugar, starch and fiber. Sugar carbohydrates and starch carbohydrates cause your blood glucose levels to rise. Fiber carbohydrates do not elevate your blood sugar. One medium-sized baked sweet potato with skin contains 7.39 g of sugar, 9.04 g of starch, and 3.8 g of fiber. This means that out of the 20.23 g of total carbohydrate in a sweet potato, 16.43 of those grams will contribute to an elevation in your blood glucose levels and trigger insulin production.
Blood Glucose Basics
After you consume a sweet potato, it makes its way to your stomach in order to be digested. In your stomach, the sugar carbohydrates found in sweet potatoes pass through the lining of your stomach and get directly absorbed into your bloodstream. Meanwhile, the starch carbohydrates from the sweet potato get broken down into glucose molecules. Once the starch is converted to glucose molecules, they go through the lining of your stomach and enter your bloodstream as well. The fiber from the sweet potato continues to make its way through and out of your body, undigested. Your insulin levels rise during the digestion process.
Eating a sweet potato causes your blood glucose levels to rise and triggers the production of insulin. When your blood glucose levels elevate, your pancreas receives a signal to secrete insulin. Insulin helps transfer glucose molecules out of your bloodstream and into various cells throughout your body. The result is that your blood glucose levels decrease and your cells receive the energy they need in order to function. Glucose is your body’s main source of energy, and insulin helps ensure that it reaches and fuels your cells.
If you have insulin resistance, your body does not respond properly to the effects of insulin. The result is that glucose molecules build up in your bloodstream, causing your blood glucose levels to remain elevated. If left untreated, insulin resistance may lead to type 2 diabetes. Persons with insulin resistance and type 2 diabetes should follow a diet that monitors their intake of carbohydrates. According to the American Diabetes Association, persons with diabetes should consume about 45 g to 60 g of total carbohydrate per meal. Sweet potatoes are a healthy complex carbohydrate choice on a diabetes diet because they are rich in dietary fiber.
- MayoClinic.com: Nutrition and Healthy Eating – Glycemic Index Diet: Losing Weight with Blood Sugar Control, Nov. 24, 2009
- American Diabetes Association: Food and Fitness – Carbohydrates
- United States Department of Agriculture Nutrient Database
- American Diabetes Association: Food and Fitness – Carbohydrate Counting
- American Diabetes Association: Food and Fitness – Diabetes Superfoods