Do People With Type 2 Diabetes Have to Follow a Low-Carb Diet?

How a low-carb diet may affect your blood sugars

Grain Salad

Verywell / Alexandra Shytsman

If you're living with type 2 diabetes, you may be wondering if you should follow a low-carb diet. In fact, a 2021 review of 23 studies suggests that a very low-carbohydrate diet may help diabetes go into remission at six months. However, results weren't sustained at 12 months. More research is needed to determine how clinicians can help sustain a diet post six months for better management of health.

Learn about the role of carbohydrates in a healthy diet for people with diabetes and what some of the current research says about the impact of low-carb or very low-carb diets on blood sugar.

The Role of Carbohydrates in Our Diet

Carbohydrates include sugars and starches and together they make up one group of macronutrients; the other two are protein and fat. When you consume carbohydrates, your digestive system breaks them down into individual sugar units that are absorbed into your blood. This triggers the pancreas to release insulin, a hormone that helps move glucose out of your blood and into your body's cells so it can be used for energy.

Sugars that aren't immediately used for energy are either stored or converted to fat (when you eat more food than your body needs). To a lower degree, insulin is also released when you consume protein but isn't problematic when the body has adequate insulin.

You need to consume carbohydrates every day because they are your body's primary energy source. The Academy of Nutrition and Dietetics and the U.S. Department of Agriculture's 2020–2025 Dietary Guidelines for Americans recommend that you get about half of your daily calories (45% to 65% of calories) from nutrient-dense carbohydrate sources, which is between 900 to 1,300 calories in a 2,000 calorie diet. These are recommendations made to promote health and prevent diseases.

According to the Institute of Medicine, the recommended dietary allowance for carbohydrates is 130 grams of carbohydrates per day. This is the average intake sufficient to meet the nutrient needs of 97%–98% of the population. But this amount will increase to 175 grams if you're pregnant.

History of Carbohydrates in a Diabetic Diet

For people with diabetes, the recommended daily intake of carbohydrates has a roller-coaster history and remains somewhat an area of controversy, according to the American Diabetes Association. Before the discovery of insulin in 1921, restrictive low-carb diets and fasting were often the only treatments available. That changed with both the discovery of insulin and diabetes medications, as well as with the knowledge gained about the role of fat in heart disease.

Since fat was considered a major culprit in heart disease, and since heart disease is common in those with diabetes, the recommended intake of carbohydrates has actually increased. Because low-carb eating plans tend to mean consuming more fat and protein, following a strict low-carb style of eating isn't always recommended.

For anyone following a low-carb diet, it's important to understand the difference between healthy fats and unhealthy fats. A low-carb diet that's too high in saturated fats is not a healthy choice for anyone. The USDA recommends that no more than 10% of daily calories come from saturated fats.

Low-carb diets have become synonymous with weight loss, which is also important for many people with type 2 diabetes. Choose sources of healthy fats like nuts, fish, and healthy oils over unhealthy sources like processed meat.

Benefits of a Low-Carb Diet for Diabetes

The following is a breakdown of the different levels of carbohydrate intake:

  • Very low-carbohydrate (less than 10% carbohydrates) or 20–50 grams per day
  • Low-carbohydrate (less than 26% carbohydrates) or less than 130 grams per day
  • Moderate-carbohydrate (26% to 44% carbohydrates)
  • High-carbohydrate (45% or greater carbohydrates)

A 2015 review looked at almost 100 different studies to determine the advantages of a very low-carb diet for people with diabetes. The authors drew several conclusions, some of which included:

  • A low-carb (very low carb) diet resulted in lower blood sugars.
  • A reduction in blood sugars on a low-carb diet didn't require weight loss, though weight loss is a common result of low-carb diets. (Learn more about weight loss on a low-carb diet).
  • People with type 2 diabetes were sometimes able to reduce the dose of their diabetic medications or eliminate them completely.
  • Changing to a low-carb diet was fairly easy.
  • There were no side effects on the low-carb diet.

The researchers concluded that a low-carb diet should be the first approach in treating type 2 diabetes.

A Balanced Diet Vs. a Low-Carb Diet for Diabetes

The Academy of Nutrition and Dietetics recommends a well-balanced diet for people with diabetes and advises consuming a variety of nutrient-dense foods, opting for less fat and salt, and choosing healthy complex carbohydrates over refined carbs. The Academy's recommendations are in alignment with USDA dietary guidelines for a healthy diet.

If your doctor recommends a balanced diet over a low-carb diet, be sure to opt for complex carbs such as whole grains, vegetables, and fruits to maintain consistency with your daily carbohydrate intake.

If you're overweight or obese, a healthy, balanced diet combined with regular exercise can help you lose weight.

Following a Low-Carb Diet

If you're interested in following a low-carb diet, talk to your healthcare provider, diabetes educator, or a registered dietician or nutritionist who specializes in medical nutrition therapy for diabetes prior to making any dietary changes. If your diabetes is more complicated, seeing an endocrinologist and certified diabetes care and education specialist is advised.

Since your blood sugars may decrease on a low-carb plan, ask your doctor about any medications you're taking while following a low-carb plan. Switching to a low-carb diet may affect your diabetes and/or blood pressure medications, especially if it leads to weight loss.

Weight loss is likely for many people following a low-carb diet. Many people experience mild side effects like low blood sugar, so it's a good idea to track your blood glucose closely. Keep a journal of your dietary intake to monitor how certain foods are affecting you. Different times of blood glucose monitoring may include when you wake up, before meals, 1–2 hours after meals, and at bedtime. In special situations, you will need to have your blood glucose checked in the middle of the night.

Many people report that the first week or so on a low-carb diet can be challenging. You may experience carb withdrawal in the first few days followed by a "carb crash" occurring roughly 3 to 5 days after you make the switch. Familiarizing yourself with the basics of a low-carb diet can help you avoid some of the common mistakes people make when starting a low-carb plan.

If you're unsure whether a low-carb diet is right for you, ask your doctor for advice. Once you have your physician's approval, you can get started by making your own delicious low-carb recipes at home.

A Word From Verywell

While some health experts argue that a low-carb diet is unnecessary for people with diabetes, there is enough research to suggest that a very low-carb diet may help people to manage the disease or be in remission.

If you're living with diabetes, always consult your doctor before making any changes to your diet. In general, going on a low-carb diet has few side effects with the exception of low blood sugar, especially if you are on glucose-lowering medications.

Although low-carb diets for people with diabetes are still up for debate, as research continues to emerge we will likely learn more about the ideal amount of carbohydrates for those living with this condition.

13 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Goldenberg JZ, Day A, Brinkworth GD, et al. Efficacy and safety of low and very low carbohydrate diets for type 2 diabetes remission: systematic review and meta-analysis of published and unpublished randomized trial dataBMJ. 2021;372:m4743. doi:10.1136/bmj.m4743

  2. Harvard Health Publishing. The smart way to look at carbohydrates.

  3. U.S. Department of Health and Human Services and U.S. Department of Agriculture. 2020–2025 Dietary Guidelines for Americans. Ninth Edition.

  4. Institute of Medicine of the National Academies. Dietary References Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. The National Academies Press. Washington, D.C.: 2002.

  5. American Diabetes Association. Understanding Carbs: Find Your Balance.

  6. Mazur A. Why were “starvation diets” promoted for diabetes in the pre-insulin period?Nutr J. 2011;10:23. doi:10.1186/1475-2891-10-23

  7. Quianzon CC, Cheikh I. History of insulin. J Community Hosp Intern Med Perspect. 2012;2(2). doi:10.3402/jchimp.v2i2.18701

  8. American Diabetes Association. Fats.

  9. Bolla AM, Caretto A, Laurenzi A, Scavini M, Piemonti L. Low-carb and ketogenic diets in type 1 and type 2 diabetesNutrients. 2019;11(5):962. doi:10.3390/nu11050962

  10. Oh R, Gilani B, Uppaluri KR. Low Carbohydrate Diet.

  11. Feinman R, Pogozelski W, Astrup A, et al. Dietary carbohydrate restriction as the first approach in diabetes management: Critical review and evidence baseNutrition. 2015;31(1):1-13. doi:10.1016/j.nut.2014.06.011

  12. Academy of Nutrition and Dietetics. Eating Right with Diabetes.

  13. Schwingshackl L, Chaimani A, Hoffmann G, Schwedhelm C, Boeing H. Impact of different dietary approaches on blood pressure in hypertensive and prehypertensive patients: Protocol for a systematic review and network meta-analysisBMJ Open. 2017;7(4):e014736. doi:10.1136/bmjopen-2016-014736

Additional Reading

By Shereen Lehman, MS
Shereen Lehman, MS, is a former writer for Verywell Fit and Reuters Health. She's a healthcare journalist who writes about healthy eating and offers evidence-based advice for regular people.