If you have type 1 diabetes, the keto diet may be appropriate, given diligent monitoring of ketone levels and approval from your doctor.

If you have type 1 diabetes and are thinking about trying a ketogenic diet, it is important to work with healthcare professionals, such as a registered dietitian and medical doctor, to avoid serious complicationsTrusted Source.

On a keto diet, you significantly reduce your carb intake to less than 50 grams per day and increase your fat intake instead. This shift in metabolism results in nutritional ketosis, which means your body uses ketones in your blood for energy.

Conversely, diabetic ketoacidosis is a medical emergency that occurs in people with type 1 diabetes if they do not take insulin. Without insulin to transport blood sugar into the body’s cells, blood sugar and ketone levels rise rapidlyTrusted Source, disrupting the blood’s acid-base balance.

Thus, the main difference between the two is as follows:

  • In ketosis, only ketone levels are elevated, allowing your body to use mostly fat for energy.
  • In diabetic ketoacidosis, blood sugar and ketone levels are very high, resulting in a critical health state.

There are few recent long-term studies on the effects of the ketogenic diet in individuals with type 1 diabetes, and the ones that do exist are case studies.

A 2024 study that followed one individual with type 1 diabetes for 10 years found that the keto diet improved blood sugar management and reduced daily insulin needs.

Another 2023 study in a 20-year-old male with type 1 diabetes found that the keto diet reduced daily insulin needs and improved quality of life.

The keto diet has been shown to significantly lower blood sugar levels in people with type 1 diabetes.

One small 2018 studyTrusted Source in 11 adults with type 1 diabetes found that the keto diet significantly improved A1C levels, a long-term blood sugar management marker.

However, some participants experienced episodes of their blood sugar levels falling too low. This can happen if your blood sugar levels drop below 70 mg/dl (3.9 mmol/L).

If your blood sugar levels become too low, you may experienceTrusted Source:

  • confusion
  • dizziness
  • slurred speech
  • loss of consciousness

Studies suggest that the keto diet can promote weight loss.

A number of factors are believed to be responsible, including:

  • Appetite suppression. The keto diet promotes feelings of fullnessTrusted Source, making you less likely to overeat.
  • Food elimination. Higher-carb foods—which can be more calorie-dense—are eliminated, which can help reduce your calorie intake.
  • Higher protein intake. Keto diets tend to be higher in protein than standard diets, increasing fullness at meals.

While some people with type 1 diabetes may be interested in losing weight, this is not the goal, or even safe, for everyone.

It’s important to take this possible side effect into consideration before starting the keto diet.

When drastically reducing your carb intake, such as with the keto diet, blood sugar levels trend much lower, requiring less insulin to manage them. Insulin dosing must be properly adjusted to account for your current blood sugar levels, which will likely be lower after starting the keto diet.

If you administer the same amount of insulin as before starting the diet, you may experience hypoglycemia (low blood sugar), a serious side effect.

Considering that less insulin is required, it’s crucial to seek medical guidance and frequently test your blood sugar levels to prevent hypoglycemia episodes.

Whether the keto diet is safe for people with type 1 diabetes does not have a simple yes-or-no answer. Many factors need to be considered.

Don’t start keto unsupervised

If you have type 1 diabetes and are interested in the keto diet, it’s extremely important to start by seeking medical guidance from a registered dietitian (RD) and your doctor.

An RD can assist you with the specific format and outline of the diet, whereas your doctor can help adjust your insulin regimen or oral medications accordingly.

Together, their supervision and guidance will greatly reduce your risk of serious complications and help you adhere to the diet safely and sustainably.

Monitor your ketone levels

When following a keto diet, you should also closely monitor your blood sugar levels and test your ketone levels regularly.

There are several methods for testing ketones:

  • Blood testing. You can purchase meters with test strips that work similarly to blood glucose meters.
  • Urine testing. You can buy test strips that indicate ketones by color when submerged in a urine sample.
  • Breath analyzer. These devices measure acetone levels, a ketone byproduct, in your breath.

You should check your ketone levels if your blood sugar level is above 240mg/dlTrusted Source or if you:

  • have difficulty breathing
  • have fruity-smelling breath
  • are vomiting

If your blood sugar levels are above 300 mg/dL, or if you experience any of the symptoms listed above, you should seek emergency services immediately.

Blood ketone meters are the most accurate and readily available online or in pharmacies. Urine strips and breath analyzers can also be purchased.

Some people should avoid the keto diet

Due to potentially negative overall health effects, some people with type 1 diabetes should not follow a keto diet, including:

  • those with a history of chronic low blood sugar levels
  • people undergoing or recovering from a medical procedure
  • children or adolescents under 18 years old
  • pregnant or breastfeeding people
  • people who are underweight or have an eating disorder

Whether the keto diet is safe if you have type 1 diabetes depends on many individual factors, such as how well your diabetes is managed or whether you’re underweight or have a history of low blood sugar levels.

If you have type 1 diabetes and want to try the keto diet, speak to your healthcare provider and a dietitian to set up a personalized program to minimize your risk of potentially dangerous side effects.