How Low (Carb) Should You Go?

Is a low-carbohydrate diet really the best way to go? Maybe for a small percentage of people.

Researchers have been debating the benefits of using low-carbohydrate diets to control blood glucose levels in people with diabetes for decades.  Starvation-level minimal carbohydrate, high fat diets were used previous to the discovery of insulin to keep people alive, and variations of lower carbohydrate diets were in vogue up to the late 1960s/early 70s when concerns about heart disease predicated the move  to a more fat-restricted, higher-carbohydrate meal plan.

The pendulum has been swinging back to the use of moderately restricted carb intake in the range of 35 to 45 percent of calories over the past decade.  This level of carbohydrate intake allows a variety of foods with choices among all the food groups.  However, a recent article appearing in the Fall, 2012 Diabetes Spectrum by Franziska Spritzler, a registered dietitian and certified diabetes educator, challenges the wisdom or need for balance and discusses the benefits to glycemic control of following very low-carbohydrate diets in the order of 20 percent of calories or less.  She also reviews and effectively rebuts some of the arguments against them, namely that they are nutritionally inadequate, overwhelmingly lead to heart disease because of elevated fat and saturated fat content and may affect thyroid levels.

It is easy to dismiss calls for the use of these type of diets when made by those outside of the scientific community but less so when the evidence in their favor are cogently presented by a member of your own trade.  Ms. Spritzler does something medical researchers almost never do—she gives an example of a real world meal based on a carbohydrate load of approximately 20% of calories.

Click to view larger

Ms. Spritzler makes some cogent arguments and there are people for whom the diet could be beneficial.  However, many Americans would have profound difficulty adjusting to its requirements.  In order to follow this type of diet a severe, and in the sample meal, total elimination of an entire food group occurs.  No grains or starchy vegetables appear at all and the fat content of the diet is elevated beyond the culinary comfort of most Americans.

Now, it is almost a truism that most patients with type 2 diabetes need to reduce their reliance on grains and star­­­­­­chy vegetables, but these foods play an important role in the diet; they provide several of the B vitamins: thiamin, niacin and riboflavin. They also form the backbone of the American food culture.  Presenting a mealplan devoid of starches is akin to asking Italians to stop using tomatoes.


In addition, the sample menu presented is based on a 2,000 calorie diet.  Many people with diabetes need to lose weight, and calorie levels for women, for example, would fall more into the 1200 to 1500 range.

While it is certainly feasible to reach the Recommended Daily Requirement Dietary Allowance (RDA) for the nutrients such as calcium without the diet’s use of dairy products, it requires a good deal more planning, and the diet may require calcium supplementation for the average American with diabetes.



  1. I read recently that there has been some debate on the usage of the glycemic index. Apparently a number of clinical studies have reported mixed results as to whether it makes that much of a difference in the end. Also, I have heard that some people have been calling into question the accuracy of the glycemic index itself. I was just wondering if this is something that you have discussed in depth?

  2. Low carb works – it takes commitment and an understanding of the rationale for using low carb – it also requires an intelligent health professional well versed in the theory and practice of low carb and is supportive of their clients endeavours.

    As a Type 2 diabetic,with poor control and an HbA1c of 7.9%, after going low carb and sticking to it, have achieved an HbA1c of 4.9% and lost 50lbs.

    It works- and is sustainable – period

    On the net, there are many support groups devoted to the low carb management of diabetes where a committed person can get information.

  3. As a Type 1, too low on the carb side means lots of severe lows, no matter how I adjust the pump! The fats and proteins just don’t provide enough energy to keep my glucose at a safe level. The patient AND their healthcare team need to to take a long hard look at the individual’s diabetes. We are all a bit different, and what works for one, may be risky for another.

  4. Spot on with this write-up, I actually think this web site needs rather more consideration. I’ll most likely be again to learn much more, thanks for that info.

    • In general we recommend a minimum of 130 grams of carb per day in line with the Institute of Medicine guidelines. Diets with fewer carbohydrates can be accommodated if they are well-planned to include all needed nutrients.

  5. I’m confused by the allusion that to lose weight, you have to reduce your calorific intake… this is not so in my experience. I’m a T2 diabetic and I have been following a lowish carb (never more than 20 grams of carbs in any one meal) dietary regime of necessity for the last 8 months… I have simply been eating to my meter… eating meals such that my blood sugars were kept within the guideline target levels to avoid complications. I have never kept detailed records, but know that I hardly eat anything starchy with the exception for me being sweet potatoes as I can tolerate a medium one in a meal. Subsequent to starting this “diet”, I have lost some 42 lbs and am well on my way to hitting my target BMI of 25. Currently have only 20lbs left to lose. Whilst following this “diet”, I have never felt ravenous or low on energy… I have never suffered from adaptation “flu” either… and the weight continues to fall off at a pond a week…

    plenty of good fatty meat, 3 eggs a day, butter, double cream, fresh salad vegetables, sweet potatoes, celeriac… never feel hungry at all, eat till my belly gauge says stop…

    • Dear Paul C,
      Often times when people severly lower their carbohydrate intake, they also lower their calorie intake even if they weren’t intentionally trying to do so.

  6. Interesting blog post! Thanks for doing it.

    I was very glad to see a mainstream diabetes publication give Ms. Spritzler’s ideas some exposure. I’m familiar with many of the science journal articles she uses to support her points. Like her, I’m convinced that many folks with diabetes would see an improvement in overall health by cutting way back on carb consumption, compared to the usual “diabetic diet.” Many of my patients have seen good results. If I were a new diabetic, I’d adopt a 20-30 gram low-carb diet initially, then consider adding more as time passed, depending on blood glucose results, among other things. I’d keep daily carb grams under 80-100.

    What we need is long-term (over five years) clinical studies comparing hard clinical outcomes of people on various diets. Outcomes like overall death rates, diabetes complications, quality of life, heart attacks, strokes, cancer, etc. Unfortunately, those studies are extremely hard (impossible?) to do.

    Admittedly, very-low-carb eating is a challenge for most folks. It’s not popular. Nine of every 10 diabetic patients of mine have never even heard of Dr. Bernstein.


    -Disclaimer: All matters regarding your health require supervision by a personal physician or other appropriate health professional familiar with your current health status. Always consult your personal physican before making any dietary or exercise changes.

    • Dear Dr. Parker,
      We agree, it would be advantegeous to see long-term clinical trials (perhaps 10 years or more) that compare the distribution of nutrients. But we also need to find more ways to work with patients within their current eating paradigms.

  7. I congratulate Ms. Spritzler for credibly shedding some light on the value of a low carbohydrate diet. I have lived with Type 1 diabetes for 29 years. Eleven months ago I received a medical diagnosis of a significant diabetes complication. I was diagnosed T1D at the age of 30 and have maintained pretty good control on my blood glucose levels with most A1c’s in the 6% range. I did suffer a few years, however, some A1c’s as high as 8.5%. I fingerstick test about 15 times per day and use a continuous glucose monitor 24/7. I am very aware of how certain foods affect my postprandial blood glucose levels.

    Subsequent to my recent diabetes complication diagnosis, I adopted a low carbohydrate diet (50-70 grams/day). The benefits to my health have been amazing! While my need for insulin dropped in half, my control markedly improved. My A1c dropped from 6.8% to 6.1% while hypoglycemia incidents fell from 2-3 per day to 2-3 per week. My glucose variability as measured by standard deviation went from 60 to 30.

    I also lost 20 pounds and stopped taking blood pressure meds because my blood pressure normalized. I have more energy than before and feel emotionally and physically better.

    I know that my story can easily be discarded as anecdotal, but the significant improvements to my health during the last 11 months are dramatic. I will never return to unhealthy high carb, low fat diet that I used for most of my adult life. Many argue that low carb eating is not sustainable. I’m here to tell you that I feel satiated and healthy eating as I do. I do not see any impediments to sustaining this way of eating.

    From my vantage point, I see a medical/nutritional establishment stuck in low fat/high carb “groupthink.” The past advice of a few dietitians over my 29 year diabetes career has not served me well. I encourage Joslin and other diabetes advocates to open their mind to a way of eating that is not only healthier but also sustainable.

  8. Thank you very much for writing this piece and raising a fascinating, relevant issue.

    It seems that Ms. Spritzler has identified a way for many people to lose weight and lead a healthier lifestyle. Yet, we hesitate, because “many Americans would have profound difficulty” eliminating grains and starchy vegetables.

    Even if not all Americans would adopt this diet, shouldn’t it be widely known and promoted as a healthy option? If Ms. Spritzler has debunked the criticisms of very low-carbohydrate diets, why aren’t such diets prescribed or suggested?

    Carbohydrates may currently “form the backbone of the American food culture,” but the medical community has an obligation to clearly inform the public of the health risks of a high-carbohydrate diet. Then, patients with diabetes can make more educated choices about their own lifestyles.

    Before I cut down to ~15 g. carbs/day, carbohydrates were very much part of my eating paradigm. I was raised on heaps of pasta, bagels and cereal in the morning, and sandwiches every day for lunch. It was challenging to change my habits, but I have since discovered new foods, and, just as importantly, I have severed my addictions to wheat, sugar, and other grains. Only a few weeks of cold turkey (pun intended) can go a long way.

    I look forward to the day when more clinical studies corroborate Ms. Spritzler’s claims. Perhaps, then, her findings will no longer be considered so radical.

  9. While it is very apparent that Joslin is not supportive of Ms. Spritzer’s findings (based on the comments of Joslin mediators), I appreciate the fact that they published this article. I have been a diabetic for 5 years. When I follow a low-carb diet, my A1c drops significantly – as much as 2 points in a 4 week period. I do struggle with it as I have a distinctly intense carb-craving mechanism, but when I have been faithful to follow the low-carb recommendations, my blood sugar profiles improve, weight begins to drop off and my LDL lipids drop while my HLD lipids increase. Now, tell me again why low-carb is bad??? Oh, that’s right….it’s hard to stick to. It really is!

Leave a Reply

Your email address will not be published.