Monitoring carbohydrate intake is one of the key ways people with diabetes can manage their blood sugar levels. People living with type 1 or type 2 diabetes should aim to get 45% of their daily calories from carbohydrates.
This advice comes from the Centers for Disease Control and Prevention (CDC).
Carbohydrates occur in many different foods, including whole grains, fruit, vegetables, and baked goods. By eating a safe amount of carbohydrates, a person with diabetes can:
- stay healthier for longer
- improve their quality of life
- reduce the risk of diabetes complications
In this article, we look at the number of carbohydrates a person with diabetes needs per day, the factors affecting this, and how to eat a suitable amount.
For females, they recommend 3–4 servings of carbohydrates, at 15 grams (g) per serving. For males, they recommend a slightly higher amount of 4–5 servings. This is equivalent to 45–75 g each meal.
According to a 2019 article, a low carbohydrate diet may work well for people living with type 2 diabetes, as it can reduce their need for diabetes medication.
However, various other factors can influence how many carbohydrates a person with diabetes needs per day at an individual level.
Other lifestyle factors that influence how many carbohydrates a person with diabetes needs include:
- physical activity level
- diabetes medications
The more active a person is, the more calories they need for energy. This can have an impact on their blood sugar levels, as well as how many carbohydrates they will need on a given day.
Weight and body fat also has an impact. According to the Obesity Action Coalition, excessive body fat can cause a person at risk of developing type 2 diabetes to have less effective insulin, which can raise blood sugar levels. As a result, people who have obesity may need fewer carbohydrates.
People with prediabetes may also benefit from lowering their carbohydrate intake. The National Institute on Aging (NIA) says that millions of older people in America live with prediabetes. Making dietary changes can help someone prevent or delay the onset of type 2 diabetes.
According to the American Diabetes Association (ADA), eating too many carbohydrates causes hyperglycemia (high blood sugar) in people with diabetes. Hyperglycemia causes symptoms such as:
- increased thirst
- frequent urination
- high blood sugar readings
If someone with diabetes continues to have high blood sugar levels, they may develop ketoacidosis. Ketoacidosis is a severe and life-threatening condition that requires immediate treatment. The symptoms include:
- shortness of breath
- breath that smells fruity
- nausea and vomiting
- a very dry mouth
A person should seek emergency help from a doctor if they notice signs of ketoacidosis.
People with diabetes can also develop complications if their blood sugar levels fall too low, which causes hypoglycemia. According to the National Institute of Diabetes and Digestive and Kidney Diseases Health Information Center (NIDDK), this can happen if someone:
- uses too much diabetes medication or insulin
- does not eat enough carbohydrates
- skips or delays meals
- increases their physical activity
- drinks alcohol without enough food
Hypoglycemia can cause mild or no symptoms, so it is essential that people check their blood glucose levels regularly. The symptoms of hypoglycemia include:
- feeling shaky or dizzy
- fast or irregular heartbeat
- personality changes
- seizures or convulsions
- loss of consciousness
Hypoglycemia requires quick treatment. Severe hypoglycemia can be life-threatening. To avoid hypoglycemia, a person should make sure their medication and carbohydrate intake match each other, that they eat regularly, and that they take any exercise and illness into account.
Many foods contain carbohydrates. According to the CDC, some common sources of carbohydrates include:
- grains and foods that contain grains, such as bread, cereal, and pasta
- fruits and fruit juice
- dairy including yogurt, milk, and cheeses
- starchy vegetables, such as potatoes and corn
- beans, legumes, and peas
- soft drinks and sports drinks
- snack foods and desserts
However, some types of carbohydrates are more beneficial than others for people with diabetes. According to the ADA, there are three broad types of carbohydrate that deserve particular attention:
- Sugar: This includes sugar from sugar cane, honey, fruits, and dairy products. Sugars can occur naturally in food, or manufacturers may add sugar to foods.
- Starch: Foods high in starch include starchy vegetables, beans, and refined and whole grains.
- Fiber: Foods that are high in fiber include fruits, vegetables, whole grains, nuts, beans, and legumes.
The ADA recommend that people get most of their carbohydrates from unprocessed carbohydrate sources, such as whole grains and vegetables, rather than white bread or baked goods.
By contrast, fiber can actively reduce blood sugar levels, aid digestion, and reduce the risk of heart disease. As such, people with diabetes should avoid foods containing added sugar and refined carbohydrates and focus on vegetables, fruits, and whole grain sources.
A person can find out the most suitable amount of carbohydrates for them by counting them. According to the NIDDK, counting carbohydrates can help someone understand how many carbohydrates they need to eat to reach their target blood sugar level.
To count carbohydrates, a person needs to:
- learn which foods contain carbohydrates
- take note of the carbohydrates on the food label, or look them up online
- add the gram measurements together to calculate the total for each meal and each day
A dietitian can also help someone find the best balance of carbohydrates, exercise, and medication, and create a plan based on their needs and preferences.
A person with diabetes should see their doctor if they are struggling to control their blood sugar levels or frequently experience the symptoms of high or low blood sugar.
Someone with diabetes should also speak to their doctor before making lifestyle changes that could affect their blood sugar levels, such as a new diet or exercise program.
If a person has symptoms of severe hyperglycemia or hypoglycemia, they must seek emergency medical attention.
In general, people with diabetes should get about 45% of their daily calories from carbohydrates. However, this may change depending on factors, such as age, weight, exercise, and the severity of their condition. People with prediabetes may benefit from a low carbohydrate diet, for example.
It is important that people talk to a dietitian or doctor to find the best balance of carbohydrates for their lifestyle.