May 14, 2009

Bad Science: The Low Fat vs Low Carb Debate

The diabetes establishment just can't get their head around the idea that cutting carbs helps people with diabetes. You can see this in the way the most recent study comparing low carb and low fat diets reports its results.

This was a metastudy just published in Diabetes Care.

Influence of Fat and Carbohydrate Proportions on the Metabolic Profile in Patients With Type 2 Diabetes: A Meta-Analysis Satoru Kodama, et al. Diabetes Care 32:959-965, 2009

Let's cut to the chase. This study which is a metastudy, glommed together the findings of 19 previous studies and concluded:
the L[ow]F[fat]H[high]C[carb] diet significantly increased fasting insulin and triglycerides by 8% (P = 0.02) and 13% (P < 0.001), respectively, and lowered HDL cholesterol by 6% (P < 0.001) compared with the HFLC diet.
Translated into English this says that when you feed low fat diets to people with diabetes, their insulin levels (if they make insulin) rise, because the high carb intake has pushed up their blood sugar, their triglycerides--the blood lipid most closely associated with heart attack--rises and their HDL, good cholesterol, drops.

Pretty straightforward. But wait. That's not all they report, because the first sentence in their results section is this: Changes in values for A1C, fasting plasma glucose (FPG), and total and LDL cholesterol did not differ significantly between the LFHC and HFLC groups.

So what they're saying is that it makes no difference in the blood sugars of people with Type 2 diabetes whether they eat a low carb or high carb diet.

And here's the punchline: the final conclusion of this study is;
However, stratified analysis indicated that the increase in triglycerides was insignificant when accompanied by energy intake restriction" and "the adverse effect on triglycerides from the LFHC diet could be avoided by restricting energy intake to a degree sufficient for the attainment of weight reduction.
This translates to, "People with diabetes should continue to eat a low fat/high carb diet. They should just eat even less calories so they lose weight."

We could debate whether people with type 2 diabetes will lose weight on any diet that increases their insulin resistance, but that's not what I'm going to do here.

Instead, I'm going to show you the glaring error in this study that makes it irrelevant to its subject. And what is that? It's the definition of "low carbohydrate." Because it turns out that the "low carbohydrate" diet being compared to the high carb diet is one made up of 40% carb 40% fat and 20% protein.

Working this out against the daily input for a typical women, 2000 calories, we find that 800 calories would be contributed by carbohydrate. Since each gram of carbohydrate contains 4 calories, this means that the "low carbohydrate diet" being discussed here--the "low carb" diet explored in 19 studies--contains 200 grams a day of carbohydrate.

Can anyone not obsessed with the need to prove the worth of the low fat diet honestly argue that a woman with Type 2 diabetes who is eating 200 grams of carbohydrate a day is eating a low carb diet?

No wonder these people with diabetes saw no difference in their A1cs. They were eating twice as much carbohydrate as even the most flexible low carb dieter would consider low carb.

And the actual carb intake here probably was worse, because these weren't normal sized women. They were people with Type 2 diabetes, most of whom were overweight who were probably eating a lot more calories than 2,000. So their actual carbohydrate intake may have been as much as 300 grams a day.

How idiotic research papers like this get through peer review escapes me. Whatever your scientifico-religious beliefs, you'd think if someone is going to use the term "low carbohydrate" in your title and conclusions, they should be describing people eating low carbohydrate diets.

A diet that is 40% carbohydrates is not a low carb diet. A low carb diet is one that ranges from 7-20% of calories coming from carbohydrates and for that woman eating 2,000 calories it would top out at 100g a day of carb.

Try that diet, and you WILL see dramatic differences in A1c.

Just this week I received another email from a happy visitor to my web site reporting this:
My A1C at dx was 10.9%, (Dec. 4, 2008). As of May 4, it was 5.2%. Mainly low carb diet and exercise , plus metformin. Surprisingly, to me, quite mild exercise.
There is no drug on the market that will make that kind of improvement in the blood sugar of a person eating a high carb diet.

But the powers that be in the diabetes establishment continue to waste paper and electrons disseminating garbage studies like the one cited above. And because they do, and because doctors only pay attention to the conclusion, not the methodology, hundreds of thousands of people with diabetes are seeing their kidneys fail, their feet succumb to gangrene, and their hearts stop.

This isn't an abstract philosophical debate. It's a matter of life and death. The American Diabetes Association who fund the journal Diabetes Care are largely funded by junk food companies (Cheerios anyone?) and the drug manufacturers whose profits will fall if the diabetes community ever discovers the power of low carb diets to control their blood sugars.

Shame on them.


sooz said...

Why don't they just ask the low-carbers how their glucose levels improved once they cut their carbs? Imagine the money they could have saved?

What will it take to stop the 'experts' from shortening people's lives with the WRONG advice?

When will people realise that low-fat often means more carbs. (Compare low-fat yoghurt to normal.)

One could almost suggest that the high carb/low fat recommendations, keep doctors writing prescriptions. Who benefits? Certainly not the patient.

Harold said...

You sound angry and you should be. It is hard for me to understand how they could have their heads planted so firmly in the sand. Hippocrates' shadow by David Newman explains some of it.

Jenny said...


I've already blogged about Hippocrates Shadow. It is indeed a Must Read book for anyone who is interested in why the health system is the way it is.

country mouse said...

everything I've read convinced me that a low-carb diet is going to help. But where can one get help when other dietary restrictions make it damned difficult. For example, in my case, I need a migraine diet and I'm lactose intolerant. This means, I don't eat dairy products except when the side effects of lactaid are worth it (i.e. ice cream). I can't eat the following migraine triggers (Omega 3 fatty acids in any food or supplement, soy, almost all nuts, peanuts, and citrus are the most potent). The end result being, i.e. what I think I can eat according to the meter and if I'm lucky, consume 1300 to 1600 calories a day. For 6 foot tall 240 pound man, this really isn't enough. on this diet, I felt better before I was diagnosed.

any suggestions for where to look for help?

Most dietitians really have a clue how to cope with migraine and diabetic diets and, I'm pretty much on my own unless somebody has a suggestion of who to work with.

Jenny said...

Most lactose intolerant people can digest hard cheese without the need for supplemental lactase as the lactose has been fermented out.

When protein powder should work too.

Eggs, meat, chicken, fish, greens, lc vegetables like asparagus, peppers, mushrooms, eggplant, green beans, broccoli, etc.

You may find that your migraines decrease with a low carb diet low enough in carbs to put you into a ketogenic state. That diet helps greatly for epilepsy. Eliminating gluten might also be worth a try.

country mouse said...

jenny, thanks for the ideas, I'm so LI that even hard cheese and whey protein cause me much discomfort. I've also tried other protein powders (hemp, egg white etc) but they are *very unpleasant*. I'll keep trying.

Anonymous said...

Country Mouse,

Many LI people can digest raw milk (un pasturized) Whether or not you can get it depends on what state you live in. Raw milk has enzymes that are not cooked out of it, that help you digest lactose.

country mouse said...

thanks jean. already tried that as a child and adult. no go. pasteurized or not, I get a bad reaction. fwiw, I usually need to take 1.5x to 2x the recommended dose of lactaid to get the same effect.

Trinkwasser said...


There are a bunch of other sensible papers on Richard Feinman's site

Meanwhile what happened to Gannon and Nuttall is appalling

Some of their research was actually financed by the ADA and should have been front page news rather than hidden away in a back room

Sadly I don't see this changing any time soon while there's profit in carbs and more profit in the drugs needed to cope with the symptoms of eating too many carbs.

I'm half convinced that they are trying to remove everyone carb intolerant from the gene pool ASAP.

The SCD girl said...

Great post! (hi, hello, how are ya) :)

If country mouse is still reading, I highly recommend trying goat cheddar. Trader Joe's has it and it is GREAT. I can't tolerate lactose or casein, and I can't drink any milk (cow or goat) but the goat cheese is OK.

You might want to look at Paleo diets, primal diets, the SCD diet. They are grain free and soy free, and Paleo diets are peanut free too.

Anne said...

Country Mouse - if you are having difficulty with hard cheese which has little lactose, you may be casein intolerant. Casein is one of the fats in cheese.

Jenny - thanks again for another insightful post. Amazing, if you change the definition of low carb to 200 carbs a day, you can "prove" low carb doesn't help. Geesh!

nonegiven said...

Casein is a protein not a fat, goats milk has less casein than cows milk.

M. Cawdery said...

I have never understood the logic of the recommendations based on the USDA food pyramid. Carbs are all absorbed as C6 sugars. Glucose is effectively a poison in the diabetic yet low fat/high carb diets are the basis of the official recommendations. The rise in obesity and diabetes is closely related to the widespread use of the food pyramid and higly processed cereal products. Surplus sugar is stored by our prudent metabolism as fat. Overload results in the failure of our metabolism, particularly as one gets older. Result diabetes and obesity.

The same is beginning to happen in dogs and cats; their processed, purchased feed is effectively high carb; these animals are carnivores.

Anne said...

Nonegiven - thanks for the correction - "casein is a protein not a fat"...I knew that! I am casein intolerant! I should not post when running out the door.

renegadediabetic said...

Restricting calories on a low fat diet just doesn't work for me. The lack of fat, plus high carb load gives me insatiable cravings. I could never handle it.

I eat much less on low carb, high fat than I did on low fat, high carb. These people will go to great lengths to bolster their politically correct dietary dogma.

TMK said...

You almost have to go on anecdotal data for this stuff because the studies that are done are skewed to a high-carb diet.

I lost 97 pounds and have maintained it for more than 7 months eating a true low-carb, high-protein diet. Plus my A1C went from an average of 7.5% to less than 5%. I've personally found it to be a way of eating I can live with, without huge cravings or hunger.

My doctor was completely baffled by a year-plus of 5-5.5% A1Cs and is starting to use me as an example for her other diabetic patients. The ADA guidelines aren't looking like such a good idea to her anymore.

Trinkwasser said...

Countrymouse, your kind of problem is EXACTLY the kind of thing that a trained and qualified professional like a dietician should be able to help with


wow what a strange dream I just had

country mouse said...


one would think. so far I've stumped 2. how many do I try? I'm getting real tired of identifying the clueless

nutrition_n said...

countrymouse - unfortunately, registered dieticians are not always adequately trained in metabolism and biochemistry and the scientific method to truly be able to comprehensively review and integrate all the research into their practice - they could be fine for some things, but not necessarily be able to go outside the box when someone has a more challenging issue. Try looking for someone who is a Certified Nutrition Specialist (through the American Institute of Nutrition) or a Board Certified Nutritionist, in addition to (or rather than) a dietitian. See here for an excellent review:
It does sound like you may be casein intolerant rather than lactose, and your pinning of migraines on omega-3's is a little hard to comprehend from a physiological/neurochemical point of view - that also could be something that's 'coming along for the ride' in the omega-3 sources.
Good luck

Jenny said...

I have run into degreed nutritionists who were as ignorant as could be about diabetes. They learned what they knew back 15 years ago and were taught that diabetics should eat starch, not fat, because fat caused heart attacks.

You can't argue with these people. They trust the people who trained them. And they do a huge amount of damage to people with diabetes because they are not educated about the impact of carbohydrates on blood sugar and many still fear hypos much more than highs--to the point where they warn people with diabetes that it is "dangerous" to let blood sugar go as low as 100 mg/dl.

I hope there are younger, more progressive nutritionists out there, but if there are the people they are helping are mighty quiet. And the horror stories about the others keep pouring in.

country mouse said...

Nutrition_N. thanks for the information on nutritionists. It looks like it'll be quite helpful.

I've never heard of casein intolerance but I will investigate. Part of the reason I thought it was lactose tolerance was that Lactaid stops the gas, pain, and associated symptoms.

With regard to omega-3/migraine connection, it comes out of my experience with omega-3 capsules apparently triggering excruciating migraines, tuna, salmon, and swordfish triggering visual aura in less than one hour.

By the way, one hour my time limit for determining if something triggers migraines. Once you get past an hour, it's really hard to figure out if the food you think is a trigger really is the trigger. Figuring out if something is a trigger is not unlike determining which foods do nasty things to your blood glucose levels. You need to consume in isolation and multiple times on different days in order to determine the effect. It's not easy to do but easy to get confused on.

It's entirely possible something else is triggering the migraines. It would have to be common to the omega-3 pills and the three types of fish mentioned above. But not common with Pollock, cod, haddock, and a variety of freshwater fish that do not give me problems.

I am so tired of being my own laboratory mouse.

nonegiven said...

You can get vegetarian DHA

country mouse said...


thank you for the suggestion. I will look for it. one interesting thing, eggs, and oils with high O3 levels always smell/taste fishy. I've given up using any oils except peanut, sunflower, and olive.

Jenny said...

Country mouse,

The Whole Health Source Blog you'll find on my blogroll (to the right of the blog posts) has a series of fascinating posts about the relationship of omega 6 oils and inflammation.