Even though the causes of type 1 and type 2 diabetes differ, part of the management of both can be the same–the ketogenic diet. Studies show that ketogenic and low-carb diets improve blood glucose control in type 1 diabetics and that it is safe long-term when you start the diet with the guidance of your treating physician and adjust insulin dosage accordingly.
You may have heard that the ketogenic diet is effective in reversing type 2 diabetes but you might not know that keto can have benefits for type 1 diabetics as well. Type 2 diabetes is the type of diabetes most commonly mentioned in the context of the ketogenic diet. Type 2 diabetes is lifestyle related and develops over time, starting with insulin resistance and pre-diabetes. Eventually, the insulin-producing beta-cells in the pancreas cannot produce enough insulin to keep the blood sugar stable, and the body’s cells don’t respond well to the insulin that is present. Type 1 diabetes, on the other hand, is an organ-specific autoimmune disease that often debuts in childhood, in which the immune system attacks and destroys the pancreatic beta-cells, eventually resulting in complete loss of insulin production. [1] Regardless of diet, type 1 diabetics need insulin injections daily to lower blood glucose and ensure that glucose in the blood can enter the cells in the body. In contrast, lifestyle changes like a ketogenic or low-carb diet, exercise, and quitting smoking enables some with type 2 diabetes to manage their condition without medications or insulin injections.
No matter what you have heard, there is no such thing as an essential carbohydrate, not even for type 1 diabetics. While there are essential amino acids and fatty acids that are obtained through the diet, even diabetics can produce the amount of glucose the body needs from glycerol (the backbone of triglyceride molecules), lactate, and some amino acids, in a metabolic process in the liver called gluconeogenesis.
Using or recommending the ketogenic diet as a part of the management of type 1 diabetes is still controversial, which likely stems from the belief that carbohydrates are necessary to avoid hypoglycemia (dangerously low blood glucose). But in fact, a diet rich in carbohydrates increases the need for insulin injections. For those with a daily food intake that includes varying amounts and types of carbohydrates, the insulin dosage may be too high in some cases, resulting in hypoglycemia. On a ketogenic diet, carbohydrate intake is very low and consistent, and therefore the insulin dosage needed is also lower and much more consistent. This reduces the chances of overdosing insulin and causing hypoglycemia. However, it is very important for type 1 diabetics to consult a physician when reducing carbohydrate intake, because insulin dosage will need to be reduced accordingly.
To prove the concept that carbohydrates are not essential, a study tested whether it was feasible for eight individuals, two with type 1 diabetes, to exercise over a 5-day period while completely fasted. The participants walked or ran approximately 20 miles per day for 5 consecutive days while only consuming water. All participants completed the study without problems with glycemic control and without any physical injuries. In the participants with type 1 diabetes, blood glucose levels ranged from less than 3mmol/L to 9mmol/L and in participants without type 1 diabetes, blood glucose levels ranged from less than 3mmol/L to 7mmol/L. Results from continuous glucose monitors showed little variability in blood glucose levels in the participants with type 1 diabetes. Ketone levels ranged from 0.3 to 7.5 mmol/L in all participants, and they felt very little hunger. Mood was not negatively affected, but actually enhanced in most participants.
The key points from the study were:
The authors conclude that the results from this study should reassure clinicians who wants to recommend a ketogenic lifestyle to patients with type 1 diabetes. [2] In other words, the ketogenic diet is safe for people with type 1 diabetes when followed by their physician.
A large online survey with adults and parents of children with type 1 diabetes (316 participants) evaluated how a ketogenic diet affected glycemic control. They looked at change in HbA1c (a blood test measuring your blood glucose level over the past two to three months) after beginning the ketogenic diet as well as the total daily insulin dose and adverse events. The daily mean intake of carbohydrates was 36g and mean HbA1c was 5.7%. The authors concluded that the participants with type 1 diabetes had exceptional glycemic control and low rates of adverse events. [3]
If you are type 1 diabetic and are following standard guidelines, you might not have to start with a ketogenic diet to achieve improved glycemic control. Even a low-carb diet has been shown to stabilize fluctuating blood glucose levels. [4] Twenty-two patients with type 1 diabetes and symptomatic fluctuating blood glucose were put on a low-carb diet with 70-90g of carbohydrate per day and insulin doses were reduced accordingly.
The purpose of the study was to reduce the blood glucose fluctuations, the number of hypoglycemia episodes and to improve HbA1c. After three and 12 months on the low-carb diet the number of episodes with hypoglycemia were significantly lowered and so were the HbA1c and triglyceride levels. Insulin requirements were also significant reduced. The authors conclude that a low-carb diet improves glycemic control and that it is a feasible and long-term alternative in the treatment of type 1 diabetes. [4]
Persons with type 1 diabetes are at risk of both severe hypoglycemia and severe hyperglycemia and controlling blood glucose levels is a constant lifelong challenge. Long-term, people with type 1 diabetes are at risk of many diabetes-related complications due to fluctuating blood glucose which harms the body’s cells and blood vessels. There is no reason for type 1 diabetics or clinicians treating patients with type 1 diabetes to fear ketogenic or low-carb diets. Lifestyle modifications are just as important in type 1 as in type 2 diabetes and with the right guidance from knowledgeable physicians and dieticians specialized in the ketogenic diet, going keto can improve glycemic control, lower medication and insulin dosages, and reduce the risk of many diabetes-related complications.
Kawasaki E. Type 1 Diabetes and Autoimmunity. Clinical Pediatric Endocrinology [Internet]. 2014 [cited 2022 Oct 25];23(4):99–105. Available from: https://www.jstage.jst.go.jp/article/cpe/23/4/23_9993/_article
Lake I. Nutritional ketosis is well-tolerated, even in type 1 diabetes: the ZeroFive100 Project; a proof-of-concept study [Internet]. Vol. 28, Current opinion in endocrinology, diabetes, and obesity. NLM (Medline); 2021 [cited 2022 Oct 25]. p. 453–62. Available from: https://pubmed.ncbi.nlm.nih.gov/34334612/
Lennerz BS, Barton A, Bernstein RK, Dikeman RD, Diulus C, Hallberg S, et al. Management of Type 1 Diabetes With a Very Low–Carbohydrate Diet. Pediatrics [Internet]. 2018 Jun 1;141(6). Available from: https://publications.aap.org/pediatrics/article/141/6/e20173349/37619/Management-of-Type-1-Diabetes-With-a-Very-Low
Nielsen JV, Jönsson E, Ivarsson A. A low carbohydrate diet in type 1 diabetes: Clinical experience - A brief report. Ups J Med Sci [Internet]. 2005 [cited 2022 Oct 25];110(3):267–73. Available from: https://pubmed.ncbi.nlm.nih.gov/16454166/