How to Use Ketogenic Diets in Patients With Type 2 Diabetes

Jay H. Shubrook, DO; Rucha J. Mehta, MD


August 27, 2019

This transcript has been edited for clarity.

Jay H. Shubrook, DO: Hi. I'm Jay Shubrook, a family physician and diabetologist at Touro University California. We're here at the 79th Scientific Sessions of the American Diabetes Association (ADA) in San Francisco.

I'm happy to have Dr Rucha Mehta with me. Dr Mehta is an endocrinologist at Apollo Hospital in India and a frequent presenter at the ADA.

I want to talk about a topic that has really been a hot topic at this year's meeting: ketogenic diets in patients with type 2 diabetes.

Dr Mehta, let me tell you about a new patient of mine who recently moved here from Southern India. She was diagnosed with type 2 diabetes about 6 years ago, 4 years before moving to the United States. Since moving here, she has had trouble managing her diabetes. Her A1c is in the mid-8% range. She has gained a fair amount of weight. She is asking me what kind of diet or program she can follow. She has heard about the ketogenic diet.

She is vegetarian, and I'm struggling to give her good advice. Do you have any advice for me about this patient?

Rucha J. Mehta, MD: Jay, this is right up my alley. As you're all aware, there are an increasing number of Indian patients in the United States. As you mentioned, the keywords [I hear about this patient's dietary wishes] are "vegetarian" and "ketogenic."

I'm currently practicing in India, where we have started using all sorts of diets for our patients. For this patient, certainly, we would begin with a detailed 3-day dietary questionnaire, which we have not yet validated.

We also ask about physical activity, dietary preferences, micronutrient intake, and how much processed food they are eating per week. We don't want out patients to be miserable while they're on the diet, so we try to take their dietary activities or practices into consideration.

In the first week after we start seeing a patient like this woman, we would evaluate her fasting glucose, postprandial sugars, and any current medications. When we begin to change a patient's diet, the first week we generally start with a low-carb diet (100 g per day), which is not, in fact, very low-carb.

For example, if our patient was consuming 200 g of carbohydrates per day—our data demonstrate that most of our patients are eating an average of 200 g of carbs per day—we would probably cut that down by 50% in the first week to a 100-g carbohydrate diet. This is not a ketogenic diet.

Shubrook: A warmup.

Mehta: A warmup, yes—the first week. Thereafter, we titrate the medications down. With a lower-carb diet, we need to cut back on the patient's medication to avoid low blood sugars. Usually, in the second week, we then begin the ketogenic diet—an Indian or vegetarian version of the ketogenic diet.

I also would like to add that if the patient is overweight, we make this a hypocaloric diet. Many of our Indian patients are considered lean diabetic patients. They are not obese, but they're overweight. Their BMI may be in the range of 27 kg/m2. So we do not want to make it very hypocaloric. If the individual is morbidly obese, that's when we would consider a hypocaloric diet.

Bear in mind that our diet usually turns out to be hypocaloric compared with the previous dietary pattern. The low-carb diet, ketogenic diet, brings carbohydrates down to 40-50 g or less. By definition, it needs to be less than 30 g, but some individuals may not tolerate that.

What I like to do in my practice is called a cyclical ketogenic diet. We put the patient on a keto diet. We monitor them with urinary ketone sticks. When they go into ketosis, that's when we will collect a blood sample, usually a day or two later. Everyone is variable. Some people go into ketosis within 3 days; some people go into ketosis after 4-5 days. It depends on your body's storage types.

When the individual is in ketosis, we collect a blood sample to document ketosis, which can be done by assessing either breath acetone or serum beta-hydroxybutyric acid levels. Then we try to encourage the patient to continue the diet for another 10-14 days, which means about 2-3 weeks of a ketogenic diet.

Shubrook: Tell me more about the cyclical diet.

Mehta: By definition, a cyclical ketogenic diet means that you do a ketogenic diet from Monday to Saturday and you take Sunday off, and then you go back again Monday to Saturday.

I have redefined ketogenic for our patients because we have a different goal. The traditional cyclical ketogenic diet works best for weight loss. We are trying to work on our patients' diabetes to see if we can help reduce the number of medications, improve glycemic control, and maybe even, in the long run if the individual can sustain it, try to reverse their diabetes.

Shubrook: So it's a metabolic diet.

Mehta: Correct. We are putting the individual into ketosis for 2-3 weeks. Then we pull them out of the ketogenic diet with an initial week of low-carb diet (50-100 g/day), and then an iso carb period (approximately 200 g/day). A few weeks later, we put them back into ketosis for another 2 or 3 weeks.

For example, in a 12-week period, they would do a ketogenic diet for roughly 5 or 6 weeks. During and again at the end of each cycle, we change their medications.

During the time in which they are on the ketogenic diet, most of my patients do not require any medications. It's amazing. They love it and they really enjoy being off the medications for those 2 or 3 weeks. Hence, they don't complain about the diet as much.

Shubrook: And if the individual feels comfortable that they can keep it up, it is going to make it more possible to do it long-term.

Mehta: Absolutely. Plus, having those 2 or 3 weeks off of cycling off the ketogenic diet helps someone to be ready and willing to cycle back on, particularly when they see their medications being reduced even during the time off the ketogenic diet. They're excited to go back on it and have the possibility of maybe reversing their diabetes.

And we add in something else that in my experience works very well: intermittent fasting. We do time-restricted feeding. Patients can eat during an 8-hour window. Then we have 16 hours where they can consume clear liquids, green teas, maybe some black coffee, but they're really not having anything that has calories or is stimulating any metabolic hormones.

So far, we have looked at 22 patients with diabetes or prediabetes, with an average duration anywhere from 8 to 10 years, mean A1cs in the 8% range, and an average BMI of 30 kg/m2, which is quite high.

We have found, within a 3-month period, that most of these patients were able to bring down their medication use by more than 50%. They dropped their weight, and their A1cs, fasting sugars, and blood pressures all got better. It's very encouraging to see these results, and hopefully we'll be able to sustain them out for a longer time. These are just initial 3-month results.

Shubrook: Long-term results are very critical.

Mehta: Yes. It'll be very exciting.

Shubrook: The patient that I originally asked you about is vegetarian, a dietary choice that is quite common now regardless of an individual's background. If someone wants to do a ketogenic-like diet but they're vegetarian, how do you approach that?

Mehta: There are a lot of myths around this ketogenic diet. It gets beaten up quite often, saying it's very high-fat, bad cholesterol. What we need to keep in mind is that a good ketogenic diet should really not have anything that's deep-fried. You're not trying to eat processed, high-fat foods. We're trying to use good fats.

In a vegetarian diet, olive oil is used as the backbone for cooking. We use almond and flaxseed bread, or what we call roti in the Indian diet. Almonds, walnuts, avocado, and chia seeds are a mainstay of the ketogenic diet.

Shubrook: Plant-based fats.

Mehta: For example, in an average vegetarian diet that we use in India for ketogenic purposes, the morning begins with a green tea, black tea, or a black coffee and what we call a cauliflower-based preparation, which is like a cauliflower couscous preparation. We also have something called sprouted moong chilla, which is like a crepe. We allow them egg whites with one yolk, and cook it in olive oil.

Lunch consists of a keto roti, which is made of almond and flaxseed. We have been able to make a good combination, which is very low-carb—less than 2 g—and it's high in fat, but the good fats. And then we include a vegetable with that and a small portion of Greek yogurt.

Dinner is usually a vegetable with something called paneer, which is an Indian cheese preparation that is not processed. You could make it at home, too, so it's really good for you. It's healthy and has protein.

This meal plan stays in the limits of the right amount of protein, includes fats, and is low-carb. It really seems to be working out for our patients, and they do variations using these food groups that we give them.

Shubrook: You shared a lot of great information today. I think, first of all, regarding my patient, I have some things I can work with. This is an exciting time as we look at macronutrient modification as a treatment for metabolic syndrome and type 2 diabetes.

Stay tuned, as I am sure we'll all hear more about ketogenic diets, intermittent fasting, and ways we can change the diet to treat and prevent type 2 diabetes.

Thank you so much for joining us today and sharing all your expertise.

Mehta: Thank you.

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