How do carbohydrates affect diabetes?

Carbohydrates tend to raise glucose levels in the blood, complicating the symptoms of diabetes. The amount that a food raises blood glucose is called its glycemic index. When you consume carbohydrates your body breaks them down into glucose and then produces insulin in your bloodstream to push the glucose to your cells. If you have diabetes and eat too many simple or complex carbohydrates, your body will be unable to produce enough insulin (as in type 1) or your body will be unable to use its insulin properly (type 2). Diabetics can eat a certain amount of carbohydrates, but should emphasize healthy complex carbohydrates like vegetables and whole grains, which tend to have a low glycemic index.

Jessica Crandall
Nutrition & Dietetics Specialist

Carbohydrates come in many forms (fruits, grains, starchy vegetables, dairy and also sweets) but when you’re a diabetic it is important to make sure you’re not getting excessive carbohydrates as all carbohydrates turn into sugar in your body when digested and can cause you to have a high blood sugar. It is important to make sure you’re not getting too little or too much—but just the right amount. Working with a dietitian/diabetes educator can help you to identify what is the right amount for you.

Toby Smithson
Nutrition & Dietetics Specialist

Carbohydrates tend to raise blood sugar levels quicker than other nutrients. This does not mean you should avoid carbohydrates, but it does mean if you have diabetes you will need to have a stronger focus on serving size and amount of carbohydrate as part of your diabetes management meal plan. Complex carbohydrate or carbohydrate containing foods with fiber content of 5 grams/serving or more will help decrease absorption of the carbohydrate and slow down the rise in blood sugar levels. We use carbohydrate as our best source of energy.

Laura Motosko, MSEd, RD
Nutrition & Dietetics Specialist

Carbohydrate in food affects blood glucose directly and must be monitored in your diet. Foods contain a combination of 3 macronutrients fat, carbohydrate and protein of which all are eventually broken down into glucose to affect blood glucose levels. Strive for healthy blood glucose levels by including healthy fats like olive oil, protein such as lean meat and carefully planned small amounts of carbohydrate found in nutrient dense legumes, beans, soy or dairy, whole grains and fruits at meals and snacks. Eat unlimited non-starchy vegetables with few carbohydrates. See a Registered Dietitian to plan nutrient and carbohydrate content of meals that are individual to your needs and lifestyle to help diabetes and promote healthy weight maintenance.

Your blood sugar can stabilize or skyrocket, depending on what you eat. Food is a mixture of fats, proteins and carbohydrates. All three are necessary parts of a healthy eating plan, but people with diabetes need to be most concerned about carbohydrates.

Carbohydrates in food end up as sugar (glucose) when they are absorbed into the bloodstream. The more carbohydrates you eat, the higher your blood sugar level. Although all carbohydrates raise blood sugar, different foods have different effects, depending on the type of food, which foods your carbohydrates are eaten with and how the food is prepared.

For people with type 1 diabetes, who must take insulin daily, balancing food intake with insulin and exercise is essential. To determine how much insulin is needed to prevent blood sugar problems, it is important to know how meals and snacks influence blood sugar levels. Generally, the more carbohydrates you eat, the more insulin you need; the fewer carbohydrates you eat, the less insulin you need. Still, only by checking blood sugar two to three hours after eating can you know the effect of different kinds and amounts of food.

Continue Learning about Carbohydrates and Health

Hidden Sugars Are Not a Sweet Surprise
Hidden Sugars Are Not a Sweet Surprise
Lord Sugar (no kidding) is the star of the BBC One’s version of The Apprentice. Sugar Shane Mosley is a three-weight world boxing champ. And WBA guard...
Read More
What foods are low on the glycemic index?
Harris H. McIlwain, MDHarris H. McIlwain, MD
These foods are low on the glycemic index: Low-fat dairy Low-fat protein, tofu, nuts and legum...
More Answers
What are refined grains?
Dr. Vinayak A. Manohar, MDDr. Vinayak A. Manohar, MD
Refined grains are grains that have been milled. The milling process gets rid of the outer coating o...
More Answers
How Does the Body Use Carbohydrates?
How Does the Body Use Carbohydrates?

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.