Is Keto Good for Diabetics? Understanding the Risks and Benefits

October 11, 2025 •

5 min read

According to the International Diabetes Federation, over 537 million adults worldwide were living with diabetes in 2021, and that number is projected to rise. Managing blood glucose is critical for these individuals, and for some, a ketogenic (keto) diet may seem like an appealing solution due to its very low carbohydrate content.

Quick Summary

The keto diet's high-fat, very low-carb approach can lower blood glucose and promote weight loss in some diabetics. However, it carries significant risks, including hypoglycemia and diabetic ketoacidosis, and is difficult to sustain long-term. Medical supervision is essential to safely navigate this eating plan.

Key Points

Short-term benefits: Some diabetics, especially Type 2, may experience improved blood sugar control and weight loss on the keto diet, often reducing their need for medication.
High risk of hypoglycemia: Individuals on insulin or specific medications face a high risk of dangerously low blood sugar due to the keto diet's low carb intake.
Diabetic Ketoacidosis (DKA): A life-threatening complication that is a particular risk for Type 1 diabetics but can also occur in Type 2 diabetics on keto, requiring immediate medical attention.
Nutrient deficiencies: The diet's restrictive nature can lead to inadequate intake of fiber, vitamins, and minerals found in carb-rich foods like fruits and whole grains.
Medical supervision is mandatory: Due to the serious risks and the need for medication adjustment, a keto diet for diabetics should only be undertaken with close monitoring by a doctor and dietitian.
Long-term sustainability is a challenge: Many find the keto diet's restrictions difficult to maintain over the long term, potentially leading to 'yo-yo' dieting and its associated health risks.
Mediterranean diet offers an alternative: Studies suggest that the Mediterranean diet can offer similar benefits to blood sugar control with better nutrient balance and long-term adherence.

What is the ketogenic diet?

The ketogenic diet is a high-fat, moderate-protein, and very low-carbohydrate eating plan that forces the body into a metabolic state called ketosis. In ketosis, the body switches from using glucose (from carbs) as its primary fuel source to burning stored fat, which produces molecules called ketones. The standard keto diet typically limits carbohydrate intake to 20 to 50 grams per day. Initially developed in the 1920s to treat epilepsy, it has more recently gained popularity for weight loss and its potential effects on metabolic health.

For someone with diabetes, the appeal is obvious: limiting the dietary component that most directly affects blood sugar levels. By severely restricting carbs, the body's reliance on glucose is reduced, which can help manage hyperglycemia.

Potential benefits of the keto diet for diabetics

Short-term studies have shown that for some individuals with Type 2 diabetes, a ketogenic diet can lead to several metabolic improvements.

Improved blood sugar control: By drastically cutting carbohydrates, the keto diet can lead to more stable blood glucose levels and reduce significant post-meal spikes. This can result in a lower HbA1c, a measure of average blood sugar over three months.
Weight loss: The keto diet promotes weight loss, which is a key factor in improving insulin sensitivity for many people with Type 2 diabetes. Studies suggest that some individuals may experience more rapid weight loss on keto compared to other diets, especially in the first few months.
Reduced need for medication: With better blood sugar control and weight loss, some individuals with Type 2 diabetes may be able to reduce or even eliminate their need for certain diabetes medications, including insulin. This must be done strictly under medical supervision, as incorrect adjustments can be dangerous.
Improved insulin sensitivity: Studies have indicated that low-carbohydrate diets can lead to improved insulin sensitivity. As the body requires less insulin to manage blood sugar, it becomes more responsive to the hormone it produces.

Significant risks of the keto diet for diabetics

Despite the potential benefits, the keto diet presents serious risks and challenges, especially for those with diabetes. Its restrictive nature and profound metabolic changes are not suitable for everyone.

Hypoglycemia (low blood sugar): For individuals on insulin or certain oral diabetes medications, the drastic reduction in carbs can cause blood sugar to drop too low, leading to a hypoglycemic event. Symptoms can include dizziness, shaking, confusion, and in severe cases, seizures. Careful medication adjustment and close monitoring are essential.
Diabetic Ketoacidosis (DKA): This life-threatening condition occurs when ketones and blood sugar become dangerously high and the blood turns acidic. While it is a significant risk for those with Type 1 diabetes, it can also affect insulin-dependent Type 2 diabetics. DKA is distinct from the milder state of nutritional ketosis sought by the diet.
Nutrient deficiencies: Restricting entire food groups like fruits, whole grains, and legumes can lead to a lack of essential nutrients, including fiber, vitamins, and minerals. Fiber is particularly important for blood sugar management.
Cardiovascular concerns: While some studies show improved lipid profiles, others indicate that the high intake of saturated fats common on a keto diet can increase LDL (“bad”) cholesterol, posing a risk to heart health, particularly for those already at increased risk due to diabetes.
“Keto flu” and other side effects: As the body adapts to ketosis, many people experience short-term side effects such as fatigue, headache, nausea, constipation, and muscle cramps.
Difficulty with long-term adherence: The diet's restrictive nature makes it difficult for many to follow long-term. Failure to stick with it can lead to a cycle of weight loss and regain, which can be detrimental to overall health.

Keto vs. alternative diets for diabetes

The keto diet is not the only option for managing diabetes through diet. Research has compared it to other, often more sustainable, eating patterns. A 2022 Stanford study compared the keto diet with the Mediterranean diet for managing diabetes.

Keto vs. Mediterranean diet: A comparison for diabetics


Feature	Ketogenic Diet	Mediterranean Diet
Carb Intake	Very low (typically <50g/day).	Moderate (includes fruits, whole grains, legumes).
Fat Intake	Very high (approx. 70%).	High, primarily from healthy unsaturated sources like olive oil, nuts, and seeds.
Nutrient Density	Can be low in fiber, some vitamins (B, C, D, E), and minerals due to food restrictions.	High in fiber, antioxidants, and a wide array of vitamins and minerals.
Blood Glucose Control	Very effective in the short term by eliminating carbs.	Effective for blood sugar control through complex carbs and fiber.
Weight Loss	Effective, especially initially.	Effective for weight loss and long-term weight management.
Cardiovascular Risk	Mixed evidence, potential for increased LDL cholesterol from saturated fat.	Strong evidence for reducing cardiovascular disease risk.
Long-Term Adherence	Often difficult to sustain due to high restrictions.	Generally easier to adhere to and more sustainable over time.

The importance of medical guidance

For anyone with diabetes, particularly those taking medication, attempting a ketogenic diet without expert guidance is extremely dangerous. A healthcare team, including a doctor and a registered dietitian, can help assess if keto is a suitable option based on individual health history, medication needs, and lifestyle. The dietitian can help plan a nutritionally complete keto diet and prevent deficiencies, while the doctor can monitor blood sugar and ketone levels to adjust medications and mitigate risks like hypoglycemia and DKA.

Furthermore, focusing on a sustainable eating plan that promotes long-term healthy habits is key to managing diabetes effectively. A registered dietitian can also help explore other evidence-based approaches, such as a Mediterranean or plant-based diet, that might be a better fit for individual needs and preferences. For comprehensive information on diabetes management and nutrition, the American Diabetes Association provides valuable resources.

Conclusion

While the keto diet shows promise for some individuals with diabetes, particularly Type 2, by improving blood sugar control and promoting weight loss in the short term, it is not a universally recommended approach. The restrictive nature and the potential for serious complications like hypoglycemia and DKA necessitate caution and, most importantly, professional medical guidance. For many, other dietary patterns, such as the Mediterranean diet, may offer similar benefits with better long-term sustainability and fewer risks. Ultimately, a personalized and medically supervised plan is the safest and most effective strategy for managing diabetes through nutrition.

Frequently Asked Questions

While some studies have shown that a ketogenic diet can lead to significant improvements in blood sugar control and even remission in some cases, it is not a cure. The restrictive diet helps manage the symptoms, but long-term maintenance is required to sustain results, and it should always be done under a doctor's supervision.

Nutritional ketosis, the goal of the keto diet, is a mild metabolic state where the body produces a small, controlled amount of ketones for energy. Diabetic ketoacidosis (DKA), however, is a dangerous medical emergency where high levels of ketones and glucose make the blood dangerously acidic. DKA is a risk for diabetics, especially those with Type 1.

For Type 1 diabetics, a keto diet is not generally recommended and carries a heightened risk of DKA. Close medical supervision, including blood glucose and ketone monitoring, is absolutely critical for any Type 1 diabetic considering this diet.

Diabetics may experience "keto flu" symptoms like fatigue, headache, dizziness, and constipation as their body adapts. They must also be vigilant for signs of hypoglycemia (low blood sugar) and have a plan to manage it, especially if on medication.

Yes. A significant reduction in carbohydrates will drastically impact your blood sugar levels. Anyone on diabetes medication, especially insulin, will require immediate and careful adjustments to their dosage under the guidance of a healthcare professional to avoid hypoglycemia.

Yes, many studies show that other diets, like the Mediterranean diet, are effective for blood sugar control and weight management and are often easier for people to sustain over the long term due to fewer restrictions.

Continuous monitoring of blood glucose is advised. Additionally, blood ketone levels should be checked regularly, as recommended by a healthcare provider, to ensure a safe state of nutritional ketosis and avoid DKA.