New Review of Macronutrients for Diabetic Nutrition

For years, the legacy of the ADA (American Diabetes Association) and the ADtA (American Dietetic Association) (now staking the claim to the name Academy of Nutrition and Dietiecs (AND)) dietary recommendations have held up, arguing that diabetics should follow a high carb, low fat diet. The flag for this fight was handed off from the ADA to AND, but the individuals involved pretty much remained the same (a group of old guard non scientists with representation from industry).

The latest incarnate of their recommendations can be read in the JADA article "The Evidence for MNT for Type 1 and Type 2 Diabetes in Adults". I read through it and found it terribly flawed, just like its predecessor. And we continue to get flawed dietary advice based on this work. This is the core substantiation that is used to educate us on appropriate nutrition for managing our diabetes.

But the cracks may be widening. The latest salvo appears in the Diabetes Care issue with the article "Macronutrients, Food Groups, and Eating Patterns in the Management of Diabetes, A systematic review of the literature, 2010" Key findings on carbohydrates seem in total opposition to the AND assessment above.

Low Carb Findings (Up to 30% of calories from carbs)

In studies reducing total carbohydrate intake, markers of glycemic control and insulin sensitivity improved, but studies were small, of short duration, and in some cases were not randomized or had high dropout rates. Serum lipoproteins typically improved with reduction of total carbohydrate intake but, with the exception of HDL cholesterol, were not statistically greater than with the comparison diet. The contribution of weight loss to the results was not clear in some of these studies.

Moderate (40-65% of calories/carbs) to High (> 65%) Carb Findings

RCTs presenting information on moderate- and high-carbohydrate diets are diverse in terms of fat and protein content as well as length of study. Only two RCTs found significant differences in A1C between groups, with one study finding significantly lower A1C with the higher-carbohydrate diet only in a subgroup analysis, and the other study finding significantly lower A1C with the lower-carbohydrate diet. In terms of CVD risk factors, LDL cholesterol improved more with a high-carbohydrate diet in one study, whereas two studies found TGs improved more with a lower-carbohydrate diet.

Based on this assessment, it seems like a no brainer. The results suggest clear improvements in blood sugar control and no identified lipid problems with low carb diets. But no research seems to support the effectiveness of high carb diets. It doesn't really help your blood sugar control and it doesn't help your lipids either. The key argument has always been that low carb diets are a CVD risk because of adverse affects on lipids. Even if you believe the lipid hypothesis, this suggestst that low carb diets are heart healthy.

What do you all think of this? Is it progress? Will Hope Warshaw read it and understand it? Will it help lead to more progressive diet assessments and recommendations?

In either case, for those of you who have to deal with nutritionists and dieticians, print this journal article out. If you get harrassment from your medical team about following a low carb diet, you can pull this study out and show them that you are following a diet with some compelling evidence behind it.

Here is what you said bsc:

But no research seems to support the effectiveness of high carb diets.

However, here is what you posted from the articles:

Only two RCTs found significant differences in A1C between groups, with one study finding significantly lower A1C with the higher-carbohydrate diet only in a subgroup analysis

Even though it's in subgroups, I think looking at subgroups is extremely important when it cones to tailoring management needs. Also, if only two studies found differences between A1c at all, then you can't really conclude that high carb is worse for A1c either.

In terms of CVD risk factors, LDL cholesterol improved more with a high-carbohydrate diet in one study, whereas two studies found TGs improved more with a lower-carbohydrate diet.

I'm not arguing that low-carb diets are not effective or are not desireable for diabetics.

However, I think it's a bit of a misrepresentation of the research you posted to state that high-carb diets cannot be effective.

Ok, so you are correct, one high carb study found a lower A1c in a subgroup. But in science, one can slice and dice data to prove anything. They key is to find an overall trend that is compelling, that has enough of an effect that it is measurable and enough data to make it believable. One study with result in a sub group does not do it for me. The other study mentioned apparently found that a lower high carb diet was better than a high high carb diet.

So I admit I have some bias. But the high carb diets did not display the overpowering beneficial impact on lipids we always hear about. And it may be possible to get good lipid results on high carb. But possible is different than all the time, and we need better evidence to support generating universal recommendations.

I believe Hope Warshaw is beyond hope:) She isn't going to admit all those books she wrote are wrong. But I think the ADA is changing very slowly and in time they will approve a low carb diet as a viable option for T2's. In time I expect to see the smiling diabetics on the brochures they give to the newly diagnosed sitting down to a breakfast of bacon and eggs or a dinner of steak and salad.

Yes I do admit I'm an incurable optimist.

I'll repeat what you posted here bsc:

Maybe I misunderstand what you are trying to say by presenting the review here. Maybe you actually disagree with the review? In which case, I apologize wholeheartedly.


Only TWO studies even found a difference in A1c and ONE study found better A1c in high-carb.

LDLs improve, in general apparently, with high carb diets and TWO studies found better triglycerides improved with low-carb.

I didn't read the review, but unless there is more to it than what you presented here, I hardly call that a trend that supports your assertion.

Yes, science can slice and dice data to mean whatever it wants to say, but if you are going to present a review that support what you assert then you either accept all of what the review says or it's pretty pointless to even post the review when you are just going to pick and choose what you want to believe or disbelieve.

I didn't read the review, I admit that. If there are is more research in the review to support what you believe then it would be good to present it here.

Othewise, your bias is clear and, imho, adds nothing to a evenhanded treatment of a issue that is of monumental importance to this community.

My goodness, Bad Moon, you'll have everyone clamouring to be a diabetic!

I'm just totally weary of trying to drag a whole herd of "blind" health care providers along. It's been one of the great disappointments of my adult life, to find that many people who are in positions of authority in the health field are just so stupid. In the meantime, as long as my A1Cs are low they have no ammo, so I just try to stay healthy and off their radar. The really sad thing is all the T2 diabetics I know who are trying to comply with the recommended diet and are beating themselves up when it doesn't work.

I agree Jan. The real tragedy of this debate is PWD thinking they are doing all they can to keep their health because they trust the medical community is delivering complete and "best care" information. I think that this is particularly bad in the case of T2's because so much of it seems to discount the reality of D. If you are getting 30 to 40% of your calories from carbs and testing once a day or less (just like the doctor says) then, really, how meaningful is your A1c?

I have a research cohort of one, but my results are striking. Going low-carb and completely eliminating grains, sweeteners (of all kinds) and chemicals/additives from my diet results in:

  • Steady (necessary) body-fat loss
  • Steady decline towards normal in my blood glucose
  • Elimination of food cravings
  • More energy, joy and vitality
  • Better-quality sleep
  • Better mobility and flexibility
  • Better vision, including night vision

These ADA, ADtA, xyz groups can debate, foot-drag and enable the multi-national food conglomerates all they want. I know for a FACT that in my body, refined carbs, simple starches, processed foods and the like are metabolic poison -- and I'm done with poison.

Bravo and ditto. My wife has the same experience and she is not diabetic.

bcs, I have followed your posts in the past as they, in my opinion, are accurate and precise. I have just reviewed Bernstein's book "Diabetic Solutions" 2011 revised. As a 46 year T1 diabetic, saddled with an insulin pump and cgm, I agree low carb is the only way to control blood sugars and to starve off standard deviations. However, I need to know how low carb does a T1 have to go before they see control to arrive at an A1C at 6 or less. Bernstein promulgates 6-12-12, but I find it too restrictive. What carb level do you use personally and is it successful in keeping your blood sugars in the 80-120 range which Bernstein says is optimal? Thanks for your input.

Alrighty, reading through, there is a lot of compelling evidence here that really show how a low carb diet shines, independent of even considering other diets:

Eleven clinical trials examined the effects of lowering total carbohydrate intake on glycemic control in individuals with diabetes. The carbohydrate content goal of the diet was very low in 7 studies (10–16) and moderately low in 4 studies (17–20).

A1C decreased with a lower-carbohydrate diet in 6 of 10 studies in which it was measured (10,14–17,20). Three RCTs found no statistically significant changes in A1C with a very-low-carbohydrate diet (11–13) and one found no difference with a moderately low–carbohydrate diet (19). Other glycemic parameters such as fasting blood glucose (FBG), 24-h blood glucose, 24-h insulin (10), and fasting insulin levels (18) decreased significantly, and insulin sensitivity increased significantly (10) on the lower-carbohydrate diet. Glucose-lowering medications were decreased for individuals following the lower-carbohydrate diet (10–12,14,17) or were more frequently decreased than in the comparison diet (16).
Each of the 11 clinical trials reported at least one serum lipoprotein. The most notable results were that HDL cholesterol increased significantly more in one very-low-carbohydrate diet group (16) and two moderately low–carbohydrate diet groups (18,20) compared with the higher-carbohydrate control diet. Also, triglycerides (TGs) decreased more in one moderately low–carbohydrate diet group (20) compared with the higher-carbohydrate control diet. Otherwise, mean changes in serum lipoproteins resulting from a lower-carbohydrate diet were typically beneficial but occurred without a comparison arm or were not statistically greater than the comparison arm.

The only discernable drawbacks were not due to experimental effects, but rather experimental design:

In studies reducing total carbohydrate intake, markers of glycemic control and insulin sensitivity improved, but studies were small, of short duration, and in some cases were not randomized or had high dropout rates.

That's good stuff.

To clarify, what you reported for high carb diets is specific to high carb diets compared to traditional diets, not compared to low carb diets, which is what I understood the comparison to be. There were 7 total studies considered in this review looking at high-carb diets.

4 found no significant differences from a traditional comparison diet.

Good stuff bsc.

High five to your wife, Randy. It's great to find something that actually work. Theories are nice; results ROCK. ;0)

Hi Laura, I agree BSC delivers some great stuff. My answer to your question is around 100. I eat to my meter and activity. I'm on MDI. Take 36 units of Lantus in the morning. Most days I use between 4 and 6 units of Apidra. Rarely over 145 or under 65. For the last year my average A1c is 5.5 (the highest being 5.6). I try to stay with low GI foods, but I do indulge, in small quantities, from time to time. I have also been doing a lot of experimenting with different foods. I know a lot of people work really hard to get a better A1c and I truly was shocked when my first one came back at 5.6 after being 12.3 at diagnosis. I really don't know why it works for me, but I'm not complaining. I don't know that it makes any difference, but I consume the majority of my carbs with snacks and not with meals. Most meals are pretty much no carb except for whatever the veggies have. The only other thing that may come into play is that I take 1000 units of r-ala each day, split between morning and evening. They say it mimicks insulin, but I have never been able to corallate that. I take it for my PN and that I can tell you is a YES it does make a difference.

Ditto on the r-ala

My wife has been low carb for almost 10 years without much in the way of breaks. That's one thing that made it much easier for me. We already had a pretty good understanding of what to do and pretty much all of our common meals were already LC. Now I'm the one that is a stickler about the carbs!

My wife adopted a low carb diet in the last year. She is a self-admitted carb addict. I do all the cooking, it was easy for her, she just had to choose what I made. And she lost a lot of weight.

Interesting but the low carb cut-off is rather different than the definition of low carb around here. A 2400 calorie per day diet which is what keeps my weight at around 150lbs. allows for 720 calories from carbohydrates per day. That comes to 180 grams which is probably twice what most of us consider low carb.


I think you should choose a carb level that suits you. Everyone is different. I choose my own targets and make my own choices about carb levels, I set aggressive targets and I am willing to spend extra time and effort on foods. I eat 50-100 g/day (I use MDI) and prepare much of my own food. I can eat food that is wonderfully tasty and satisfying and keep my blood sugar tightly controlled. But everyone is different and has a different situation. I just want to be able to make a low carb dietary choice and not be considered a pariah.

I think you are right on target with this observation. The ADtA assessment defines low carb as anything below 45% of calories from carbs, a level that I hardly consider low carb. As you note, on a 2400 calorie diet, that is 270 g of carb/day, that is really, really not low carb. It is not surprising that it is difficult to see any benefit.

Frankly, I can't really imagine eating 270 g of carbs per day and keeping the krispy kreme donut bits out of my hair.