Is Exceptional Control of Type 1 Diabetes Possible with a Low-Carbohydrate Diet?

Is Exceptional Control of Type 1 Diabetes Possible with a Low-Carbohydrate Diet?

Our study in the journal Pediatrics is available here. An accompanying commentary (worth reading) is available here. And a NY Times article about our findings, with a patients’ perspective, is available here

The biggest challenge facing people with any form of diabetes, and especially type 1 (“juvenile”), is controlling blood sugar around meals.

After eating a lot of carbohydrate, blood sugar rises rapidly for 1 or 2 hours. But the insulin needed to control that rise can cause low blood sugar later.

Despite the latest technologies for monitoring blood sugar and administering insulin, most people with type 1 diabetes mellitus (T1DM) face a kind of Charybdis or Scylla choice with every meal:

HYPERglycemia soon after eating versus HYPOglycemia after a few hours

For this reason, most people with T1DM have high HbA1c values (a measure of long-term blood sugar control), indicating substantial long-term risk for serious complications like kidney failure, blindness and limb amputation.

A conceptually appealing approach to improving diabetes control is a low-carbohydrate diet. With fewer carbohydrates (especially fast-digesting grain products, potatoes and sugary foods), blood sugar rises and falls more gently after eating, making for an easier target to hit accurately with insulin. And people on a low-carbohydrate diet require less total insulin, potentially providing metabolic benefits for weight control and heart disease prevention.

Interest in carbohydrate restriction and ketogenic diets (near total elimination of carbohydrate) for type 2 diabetes — the kind associated with obesity in adults — has recently grown, with publication of several promising pilot studies. However, low-carbohydrate diets are currently not recommended for T1DM, in which the body can’t make any insulin, for fear of complications like ketoacidosis, severe hypoglycemia and poor growth in children. This, despite the fact that an ultra-low-carbohydrate/high-fat diet was the most effective treatment for severe diabetes before insulin was discovered. Presently, the American Diabetes Association suggest a diet with 45% carbohydrate, including 45 to 60 grams per meal (although they also encourage individualization).

Making the Connection

I hadn’t given much thought to carbohydrate restriction for T1DM before meeting Dr. Carrie Diulus at a nutrition conference in 2016. Carrie is an orthopedic surgeon with T1DM who maintains NORMAL HbA1c levels on a very-low-carbohydrate diet.

As an endocrinologist, I’ve taken care of people with diabetes for more than 20 years. I’ve never seen someone with T1DM and normal HgA1c after the initial “honeymoon period.” And if I did, I would have expected that person to have an unrecognized hormone problem and frequent, severe hypoglycemia. Carrie was the picture of health. What’s more, she said her diabetes control wasn’t the exception, but the rule in a large social media community of children and adults following a very-low-carbohydrate diet and other recommendations of Dr. Richard Bernstein.

The Study

So, being a researcher at heart (and at work as my day job), I suggested we do a scientific survey of that community. A survey is what’s known as an “observational” study — not a clinical trial. But to document a phenomenon thought not to exist by most diabetes professionals, an observational study is the right first step.

After obtaining ethics approval from Boston Children’s Hospital, and as led by Dr. Belinda Lennerz, we and our collaborators studied about 300 members of the TypeOneGrit Facebook group, including adults and parents of children with T1DM. To conduct our study with as much rigor as possible, we also contacted diabetes care providers and obtained medical records: 1) to confirm that our participants actually had T1DM; and 2) to verify the laboratory tests and other clinical outcomes.

The Results

As hypothesized, the average HbA1c among our participants was 5.67% — in the normal range and well below the average values for people with T1DM of 8.2%. Quite a few of our participants had values in the 4% range (!!!).

Reassuringly, participants reported low rates of complications like diabetic ketoacidosis and severely low blood sugar. We found no evidence for an adverse effect on growth among children. And overall, cardiovascular risk factors were excellent, with a triglyceride to HDL-cholesterol ratio of 1.0, indicative of exceptionally low insulin resistance (though LDL cholesterol was elevated, probably due to high saturated fat consumption).

These findings suggest that a low-carbohydrate diet might help prevent the long-term complications of diabetes — a possibility that needs to be explored in high quality randomized-controlled trials.

How did study participants feel about this approach, which involves life-long restriction of many high carb stables of the modern Western diet?

Mostly, really good! They expressed high levels of satisfaction with their diabetes management and health. However, a substantial minority reported conflict with their diabetes care providers. Some were lectured about having such a low HbA1c and the “dangers” of restricting carbohydrate in diabetes. Some parents didn’t even tell their child’s doctor about the low-carbohydrate diet, out of fear that they’d be accused of child abuse. This distrust, more than any diet, could set the stage for a catastrophic event, if a patient doesn’t seek professional help at times of need, and makes diabetes management decisions beyond their competencies. We hope that, with greater awareness of the low-carbohydrate diet for diabetes, misunderstanding between patients and providers can be bridged — to the benefit of all involved.

What’s Next?

Our study has several important limitations. We don’t know the long-term safety and effectiveness of very-low-carbohydrate diets among the broader population with T1DM. Our participants were evidently highly motivated, and may not be representative of all people with T1DM. Other important questions await further study, such as whether less severely restricted diets (ie, allowing more whole fruits, beans and perhaps modest amounts of whole kernel grains) might provide qualitatively similar benefits; how best to dose insulin in conjunction with carbohydrate restriction and physical activity; and how to manage acute illness, when blood sugar and ketone levels rise. Therefore, the results of this study do not by themselves justify a change in diabetes management.


These limitations notwithstanding, our findings raise the possibility that much better diabetes control than currently thought possible might be achievable — with the hope of preventing feared long-term complications. After many decades focused almost entirely on new (and expensive) drugs and technology, it’s time to refocus on the medicinal power of diet.

  • Sally Ann Clark

    Hi Dr. Ludwig, I am so happy to see this study come out. Thank you for being the researcher to push this.

    I think it will be a game changer for opening the discussions for T1D. Finally recognition for Dr Bernstein after all these years. Good thing he’s still going strong to enjoy the accolades and rebirth of hope for more PWD. The current keto movement also makes this good timing into a population that is becoming generally more accepting, as they see clear results. The works by Virtahealth are also successfully pushing low carb for the T2 community.

    A lot of the criticism I see is that there are no long term studies of the ‘complications’ of having ketones present. I for one Know that high blood sugars and high insulin levels together cause complications. It is unknown whether long term nutritional ketosis will have consequences? My bet, is that long term nutritional ketosis is adaptive and will not have negative consequences when present along with a nutritious low carb diet. I know which side I’m placing my bets with; sure complications or possible (but unlikely and unknown) complications from nutritional ketosis levels of ketones….. with stable and steady and very close to normal non-diabetic blood sugar levels.

    So, is there a plan to study further on long-term consequences? Even as on maybe a case study basis, using again members of the Typeonegrit group? I for one am going on 10 years with diabetes and taking insulin following low carb, with an a1c of close to 5.0 even though 2 pregnancies. No known complications. Diabetes has become a liveable condition that doesn’t control my life and doesn’t even take large amounts of time or attention these days. I would be delighted to provide (and have my doctor provide) additional data and laboratory tests for a further study. I am sure there would be 10 or 20 people, maybe more who have 5 or more years following this way of eating, to provide subjects for a study of ‘long-term’ adherents to this way of eating. Enough to get attention. Medical history, historical results, food monitoring (maybe several weeks, spread over a couple of months) using a commercially available tool such as chronometer which tracks macros and nutritional status (Marty Kendal of Optimising Nutrition, is also developing tools), and then current test results for critical parameters (lipid profile, liver, kidney, eye, presence of neuropathy, among others – I guess could be acceptable from any commercial medical laboratory/ centre), to assess presence of complications.

    I am excited for what this means! There is a large community here ecstatic at what you and your colleagues are doing, and wanting to support you and get the word out.

  • Don Reitsma

    A low carbohydrate diet was the treatment for T1DM before Banting and Best invented exogenous insulin in order to extend life. Did you do any kind of literature search before the study?

  • Ben Fury

    Outstanding study, Dr. Ludwig!!!

    Dr. Bernstein’s been treating T1D and T2D patients with this regimen for 35 years while the ADA and others have pooh poohed his approach. This is long overdue vindication that Bernstein’s method WORKS!

    I’m looking forward to RCT’s from your group and the Swedish group. Proof of concept is accomplished. Now, RCT affirmation is next and THEN we can FINALLY make this STANDARD OF CARE!

    In the meantime, groups like Type One Grit and SUGARbriety will continue to spread the word to the diabetic community. You CAN have normal blood sugars. You DON’T have to have diabetic complications. Ditch the sugar. Ditch the starch. Eat your meat WITH the fat and green leafy vegetables. They’re GOOD for you!

    ​Be well,
    Ben Fury
    Executive Director
    SUGARbriety International Inc
    Saving the world from sugar addiction.

  • Yvette La-Garde

    My sister has had Type 1 diabetes since she was 15 (she is in her mid-50s now). Based on studies I have read (including this one), I have really been promoting this style of eating to her. She tends to wait until she gets too low then has to over respond by taking in juice which then starts a cycle of her blood sugar rising dramatically. I have always advocated getting ahead of the curve and managing blood sugar levels with complex carbs to avoid the huge swings. With this new study, I really like the idea of getting even more control by significantly cutting back on the simple/total carbs. What I find interesting is that her diabetic doctor wants her Alc to be what I would consider pretty high (in the 7s). Sometimes I feel that diabetic doctors and their nutritional staff are just not up on the nutritional aspects of managing the disease (still promoting toast….)

  • Jani

    I’ve been on a low carb diet now for 3 years — my A1c is not stellar, but it went from 15 to 7 in the first 3 months of my new eating style, and has remained between 6.8 and 7.2 now for 3 years. I think the perceptions in the medical community are switching (though there may be some recalcitrant members who are digging their heels). Personally, both my endocrinologist and my regular doctor are completely on board and very supportive with LC, keto, and fasting (which I have started doing, with very exciting results). I think that even the ADA is cautiously moving forward now.

  • Adhere Gear

    Great Article. The truth is, everything has carbohydrates in it. All veggies, fruits, you name it. Carbohydrates are not the culprit that makes type 1 or type 2 difficult. In my experience it is the meats and the heavy grains. Both of which are very very difficult to break away from in our modern diets. Almost everything on a basic level in the average grocery stored contains meat bi products as well as grains mixed in. Diabetes in my experience is an intense mind game and a set of chemistry questions each and every day. One day your chemistry is one way because you drank a few cups of coffee, the next day your internal chemistry shifts because you slept one hour longer. Each and every decision in a diabetics life has a profound impact on the big picture for the day. Discipline and consistency are the only way to clearly identify these factors. My studies have shown me that grains and meat are extremely difficult to process, hence leading towards the concept of the Keto diet being extremely valuable to someone with an autoimmune condition. It took me 20 years to come to this conclusion after 100’s of thousand of beta tests on myself. The meats and the dense grains are make the body dependent on external insulin injections in order to burn the fuel efficiently, ie the insulin being the key to open the door for the cells to accept the fuel. Most are not aware that there are other keys on the key ring that can be used, and some fuels such as veggies, do not require such a custom key like insulin in order to process as a fuel for the body to operate. And in all honesty, grains and meat is like the “87 fuel source” while veggies, proteins, fats, and others are more like the “93 fuel source”. The catch for most is to understand that when one removes a lifestyle and diet they have been consuming for years, that there is a price to pay, that price is an adjustment period for the body to get acclimated to its new fuel source. This means a chemical transformation that occurs inside the body, differing in period length from person to person since everyone has their own custom set of fuels and foods they consume on a daily basis. So, in my experience, the solution above is quite accurate, but taking it to the next level of eliminated all grains and eliminated meat, allows a type 1 to have even great control over their metabolism and ultimately their efficiency in burning fuel and the lack of need for insulin to be injected. Insulin dependent diabetic since age 10, 25 Years. I am not a medical doctor, nor giving medical advice, just my experience. Cheers.

  • Rachel Zinman

    wow! I live with T1D and have been on a low carb diet for the last 6 years and have had amazing control. It’s so great to read this study. Thank you!

  • Yliya Botsion

    These limitations notwithstanding, our findings raise the possibility that much better diabetes control than currently thought possible might be achievable — with the hope of preventing feared long-term complications.