Can a keto (ketogenic) diet cause diabetic ketoacidosis (DKA) in individuals with diabetes?

Ketogenic Diet and Diabetic Ketoacidosis Risk

A ketogenic diet can trigger diabetic ketoacidosis (DKA) in individuals with diabetes, particularly those with type 1 diabetes or those taking SGLT2 inhibitors, and should be approached with extreme caution in these populations.

Risk Factors for DKA on Ketogenic Diet

The risk of developing DKA while following a ketogenic diet varies significantly based on several factors:

Type of Diabetes

• Type 1 Diabetes: Highest risk due to absolute insulin deficiency 1
• Type 2 Diabetes: Lower risk but still present, especially with certain medications 1
• No Diabetes: Very low risk (0.04 per 1000 person-years) 2

Medication Use

• SGLT2 Inhibitors: Significantly increases DKA risk when combined with ketogenic diet
  • 2.90 per 1000 patient-years in people with type 2 diabetes on SGLT2 inhibitors and ketogenic diet 2
  • Relative risk of DKA with SGLT2 inhibitors: 2.46 (95% CI 1.16–5.21) 1

Other Risk Factors

• Prolonged fasting 1, 3
• Dehydration 1
• Excessive alcohol intake 1
• Presence of autoimmunity 1
• Pregnancy (can present with euglycemic DKA) 1

Mechanism of Ketogenic Diet-Induced DKA

A ketogenic diet works by restricting carbohydrates to induce ketosis. In people with diabetes, especially with insulin deficiency, this can lead to:

1. Severe carbohydrate restriction causing increased ketone production 4
2. Insufficient insulin to suppress excessive ketogenesis
3. Development of metabolic acidosis despite potentially normal blood glucose levels (euglycemic DKA) 4, 5

Clinical Presentation of Ketogenic Diet-Induced DKA

Ketogenic diet-induced DKA may present atypically:

• Euglycemic DKA: Blood glucose <200 mg/dL with ketoacidosis 1, 4, 5
• Symptoms: Nausea, vomiting, abdominal pain, fatigue, malaise 4, 5
• Laboratory findings: High anion gap metabolic acidosis, elevated ketones in blood/urine 4

Prevention Strategies

For individuals with diabetes considering a ketogenic diet:

1. Medical Supervision: Always consult healthcare provider before starting 6
2. Medication Adjustment:
   • Insulin dosage may need adjustment 1
   • Consider avoiding SGLT2 inhibitors or using with extreme caution 1, 7
3. Monitoring:
   • Regular blood glucose monitoring
   • Check ketone levels when glucose exceeds 200 mg/dL or during illness 1
4. Hydration: Maintain adequate fluid intake 1
5. Carbohydrate Intake: Consider less restrictive low-carbohydrate approach rather than very-low-carbohydrate diet 1

Special Considerations

For Type 1 Diabetes

• Very high risk: Ketogenic diets are generally not recommended 1, 3
• Never omit insulin: Continue basal insulin even when not eating 1, 6
• Sick day management: Have clear protocols for illness 6

For Type 2 Diabetes on SGLT2 Inhibitors

• Consider alternative medications if pursuing ketogenic diet 7
• Regular ketone monitoring recommended 2
• Immediate medical attention if symptoms of DKA develop 1

Warning Signs Requiring Medical Attention

Seek immediate medical care if experiencing:

• Persistent nausea/vomiting
• Abdominal pain
• Difficulty breathing
• Confusion or altered mental status
• Elevated ketone levels with symptoms 1, 6

Conclusion

While ketogenic diets may offer benefits for glycemic control and weight management in some individuals, they carry significant risks for DKA in people with diabetes. The risk is particularly pronounced in those with type 1 diabetes and those taking SGLT2 inhibitors. Current guidelines from the American Diabetes Association advise caution with very-low-carbohydrate eating plans in these populations 1.