The Low-Carb Diet Controversy in Patients With Diabetes

How cool is this? Today’s Dietitian’s RD Lounge! I am so excited about this blog—a place where I can read about and solicit the opinions and insights of my fellow colleagues. In fact, I’m interested in your opinion on the controversy surrounding low-carbohydrate diets for people with diabetes.

In the August 2016 issue of Today’s Dietitian I wrote an article titled “Low-Carb Diets and Diabetes.” In the article I discuss carbohydrate recommendations over the past century—which have ranged from low to high. Before the discovery of insulin, diets for people with diabetes were low in carbohydrate and high in fat. After the discovery of insulin, carbohydrate recommendations began to increase reaching a high of 65% of total calories per day in 2004. Moreover, the American Diabetes Association’s (ADA) 2004 nutrition guidelines stated that low-carbohydrate diets with less than 130 g per day weren’t recommended. And finally, in the latest ADA nutrition guidelines for people with diabetes issued in 2013, we were told that there was no conclusive evidence of an ideal amount of carbohydrate intake for people with diabetes. Furthermore, after a review of current evidence in 2015, the Academy of Nutrition and Dietetics’ Evidence Analysis Library concurred that there’s no ideal amount of carbohydrate intake for people with diabetes, and collaborative goals should be developed with the person who has diabetes based on individualized assessment of current eating patterns, preferences, and metabolic goals.

Yet, as I browse through various diabetes LISTSERVs, Twitter feeds, and websites, conduct interviews, and review books about diabetes, it’s clear, despite the guidelines and expert advice, that low-carbohydrate diets for people with diabetes remain a source of controversy among nutrition professionals and patients. Why? Do you think it’s personal bias?

I recently conducted an online survey of people with diabetes. One of the questions I asked was “What ticks you off most about your diabetes educator or dietitian/nutritionist?” Here are a few of the responses:

  • “Why has every CDE and dietitian I’ve seen attempt to cajole me into eating more carbohydrates?”
  • “Only consult [endocrinologists]. Hate dietitians—too self righteous.”
  • “She is a strict believer in ADA guidelines.”
  • “They always ‘forget’ what diabetes is like in real-life situations. Never understand that each situation is always different.”
  • “They know little that’s actually helpful. It’s harsh, but I’ve been hearing the same exact recommendations for the 18 years I’ve had [type 1 diabetes] and the recommendations are not even remotely helpful—usually too starch and fruit heavy, which would lead to huge [blood glucose] roller coasters for me.”

Do you think these survey respondents received individualized care?

One of the arguments against low-carbohydrate diets is that they’re unsustainable long term. However, Richard K. Bernstein, MD, a well-known proponent of low-carbohydrate diets and who has type 1 diabetes, has followed a very low-carbohydrate diet—30 g per day—for more than 40 years. He maintains normal blood glucose and lipid levels and has no diabetes-related complications. Granted, he’s one individual, and the carb count is very low, but doesn’t his case speak to sustainability? I think it also speaks to the need for individualization and monitoring outcomes. Bernstein has a large number of followers—particularly in the online community, also touting the benefits of low-carbohydrate diets.

In my article for Today’s Dietitian, I also reference a retrospective study in which individuals with type 1 diabetes were instructed to consume 70 to 90 g of carbohydrate per day for up to four years. Those with good adherence experienced a significant decrease in HbA1c, a dramatic reduction in hypoglycemic episodes, and improvement in lipid profiles. Bernstein attributes a reduction in hypoglycemia to what he calls the law of small numbers. He says it’s easier to match a small amount of carbohydrate with the appropriate amount of insulin in a way you can’t with a large amount of carbohydrate.

I think we all can agree that both the quantity and type of carbohydrate in a food influence blood glucose levels, and the total amount of carbohydrate patients eat is the primary—emphasis on primary—predictor of glycemic response. Research scientist Maggie Powers, PhD, RD, CDE, at the International Diabetes Center at Park Nicollet in Minneapolis, and president of health care and education at the ADA, says “The best guidance is to use glucose pattern management to assess the glycemic impact of a particular food plan and discuss next steps if target goals aren’t met. For some, this may be a decrease in carbohydrate, for some a redistribution of carbohydrate …”

As nutrition professionals, we must embrace both the art and science of diabetes management. It requires an open-minded approach, remembering that the best diet for our patients is the one they will follow. We shouldn’t assume it will be too difficult for the patient to follow. We must review the current evidence and provide patients with the pros and cons of low-carbohydrate diets. Then, together, decide on the approach—low-carbohydrate or otherwise—monitor the outcome, and make adjustments accordingly.

What are your thoughts?

— Constance Brown-Riggs, MSEd, RD, CDE, CDN, is past national spokesperson for the Academy of Nutrition and Dietetics, specializing in African American nutrition, and author of The African American Guide to Living Well With Diabetes and Eating Soulfully and Healthfully With Diabetes.

9 Comment

  1. I also see many studies and found this truth, that low-carbohydrate diets can cause diabetes and sometime heavy weight. Diabetes people should take carbohydrate according to doc’s guide.

  2. Interesting articles to add to our body of knowledge….

    Snorgaard O, Poulsen GM, Andersen HK, et al Systematic review and meta-analysis of dietary carbohydrate restriction in patients with type 2 diabetes BMJ Open Diabetes Research and Care 2017;5:e000354. doi: 10.1136/bmjdrc-2016-000354


    Stentz FB, Brewer A, Wan J, et al Remission of pre-diabetes to normal glucose tolerance in obese adults with high protein versus high carbohydrate diet: randomized control trial BMJ Open Diabetes Research and Care 2016;4:e000258. doi: 10.1136/bmjdrc-2016-000258

  3. Thanks, For many years, low-carb diets were not controversial for people with diabetes but rather sensible advice.

    However, that changed towards the end of the twentieth century when fat, somewhat unfairly, became associated with heart disease.

  4. I read an article about this issue yesterday, low carbohydrate diet for diabetics. I agree that the individual cases can vary between people, so it needs to be seen at a case per case basis. I like how one of the patients you surveyed said that consulting an endocrinologist is better than a dietitian – there’s a good point there.

  5. Patient here, not RD but the comments were spot on to my experience. I was ill as a child and treated with very high doses of prednisone. As an adult, I was diagnosed with Celiac and 10 years later with elevated blood sugar levels. Dr. Bernstein’s book helped me understand what was happening and get back to healthy levels. The dietitian I saw literally told me I needed to double my carbs and said low carb is unsustainable. Please. I’ve been gluten free for 13 years, carbs are just another thing to consider.I also was surprised at how little the dietitian knew about the gluten free diet. I need a health partner to help me with questions but I went to an endocrinologist. He’s been helpful.

  6. Great post! Very interesting replies from some of the patients. To me, the best part of being a registered dietitian is to understand the client’s perspective and then collaborate to help them meet their goals. The argument about low vs. higher carbohydrate depends on so many variables such as timing, medication, food sources, patient preferences and physical activity. We know that physical activity is extremely powerful in maintaining insulin sensitivity as demonstrated in the Diabetes Prevention Program. It’s important that we always look at medical nutrition therapy in the context of promoting active lifestyles, especially among those at risk for, or who have diabetes.

  7. I really enjoyed this post. I work at a Metabolic Syndrome Clinic one day each week and one of the doctors believes in a very low carbohydrate lifestyle based on individual case reports. While I agree that this may work for some, it is very difficult with our client population, which is very low income/homeless. I agree with prior comments that it can cause negative effects and can be difficult to maintain a very low carbohydrate diet. Thank you for bringing up this issue. I have to admit that I am a little hurt by the negative comments about RDs.

  8. Agree with the need to individualize based on the individual. If lower carb eating works well for a person than RDs can work with them to help ensure adequate nutrition through lower carb eating. Most people who reduce carb intake do not end up meeting very low carb diet criteria. Carbohydrate exists in three of the four food groups. A very low carb diet therefore limits food options and variety in the diet. Very low carb diets can be low in fibre, adherence rates are low in most studies, it can increase the risk of low blood sugars, and they have been linked with lower energy levels, lower exercise performance, and lower mood (carbs are needed for serotonin to enter the brain). Moderation and variety tend to be the RD mantra, including with diabetes nutrition education. Most dietitians would not advise cutting out all fruit, dairy products, and whole grains to save on carbohydrate. All foods can fit on a moderate carbohydrate diet.

  9. I like the fact that you put that question out there. Personally, I think too high of a carb diet is exactly as Bernstein described, and I don’t think RDs should be pushing high CHOs, especially if a lower CHO diet is working for the patient. However, I disagree w/ Bernstein regarding limit of 30 gms/day. I think there is a happy medium for most clients. Too low of a carb diet is difficult to follow long term, much more difficult to meet energy & nutritional needs, and is less palatable. Approximately 135 gms of CHO per day works well for me. I have low blood sugar, so I try to follow 30 gms per meal & 15 gms per snack–always w/ protein at each one.
    Just my opinion, with a lot of life experience, and some nutritional ed mixed in also!
    Thanks again for your post.

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