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jc3737 posted:
Am J Physiol Endocrinol Metab. 2013 Aug 27. [Epub ahead of print> Impaired glucose tolerance in rats fed low-carbohydrate, high-fat diets. Bielohuby M , Sisley S , Sandoval DA , Herbach N , Zengin A , Fischereder M , Menhofer D , Stoehr BJ , Stemmer K , Wanke R , Tschöp MH , Seeley RJ , Bidlingmaier M . Source1Medizinische Klinik und Poliklinik IV, Klinikum der LMU.
Abstract
Moderate low-carbohydrate/high-fat diets (LC-HFDs) are widely used to induce weight loss in overweight subjects, whereas extreme ketogenic LC-HFDs are used to treat neurological disorders like pediatric epilepsy. Usage of LC-HFD for improvement of glucose metabolism is highly controversial: some studies suggest that LC-HFDs ameliorate glucose tolerance whereas others could not find positive effects of these diets or reported impaired insulin sensitivity. Here we investigate the effects of LC-HFDs on glucose and insulin metabolism in a well-characterised animal model: rats were fed isoenergetic or hypocaloric amounts of standard control diet, a high-protein, "Atkins-style" LC-HFD, or a low-protein, ketogenic, LC-HFD. Both LC-HFDs induced lower fasting glucose and insulin levels associated with lower pancreatic ß-cell volumes. However, dynamic challenge tests (oral and intraperitoneal glucose tolerance tests, insulin-tolerance tests and hyperinsulinemic-euglycemic clamps) revealed that LC-HFD pair-fed rats exhibited impaired glucose tolerance, and impaired hepatic and peripheral tissue insulin sensitivity, the latter potentially being mediated by elevated intramyocellular lipids. Adjusting visceral fat mass in LC-HF groups to that of controls by reducing the intake of LC-HF diets to 80% of the pair-fed groups did not prevent glucose intolerance. Taken together, these data show that lack of dietary carbohydrates leads to glucose intolerance and insulin resistance in rats despite causing a reduction in fasting glucose and insulin concentrations. Our results argue against beneficial effects of LC-HFDs on glucose and insulin metabolism, at least under physiological conditions. Therefore, use of LC-HFDs for weight loss or other therapeutic purposes should be balanced against potentially harmful metabolic side effects.
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engineerguy responded:
Hi jc,

WoW. This is a pretty clear condemnation of ketogenic diets, high protein or low protein. The LC-HF diets increase visceral fat, and reduce insulin sensitivity.

Thanks for finding this! And, this does not include that the high protein diets are worst for keeping the weight off, as shown by the National Weight Registry, as well as Dr. Atkins and Jimmy Moore personally, who could not keep the weight off themselves. And the ketogenic diet promotes calciuria and osteoporosis. Not a lot to recommend it...

Best regards, EngineerGuy
 
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anon43 responded:
This is not news. Atkins in his first book, I believe, tells people to go off his diet for a few days before a glucose tolerance test otherwise they will test diabetic. I wonder how the researchers would explain the fact that so many of the low carbers, even those with diabetes, have normal HbA1C numbers? I do know that many on the diabetes support groups report low numbers but a good many of them are on drugs and insulin. And some dispute the value of a glucose tolerance test. I would love to see a study of what happens over time with those diabetics on a lc/hf diet.

dolores
 
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engineerguy replied to anon43's response:
Hi Dolores,

Re: " I wonder how the researchers would explain the fact that so many of the low carbers, even those with diabetes, have normal HbA1C numbers?"

If the diet is very low in carbs, the blood sugar is low. Before insulin was available, this was how diabetes was treated. But we agree that this is not a healthy alternative. Pritikin and Esselstyn are very low fat and high carb, but have low glucose readings, because the diabetes improves.

Best regards, EngineerGuy
 
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engineerguy replied to engineerguy's response:
Hi folks,

Quote from the article: "Adjusting visceral fat mass in LC-HF groups to that of controls by reducing the intake of LC-HF diets to 80% of the pair-fed groups did not prevent glucose intolerance."

WoW. Reducing calories by 20%, for the Low Carb High Fat diet, to reduce the visceral fat to that of controls, still left the LC-HF group with worse glucose tolerance. Cutting calories by 20% is very extreme !!

We know that being lean, and exercising, is heart healthy. The Masai are very lean and exercise plenty (at least, in the 1970's), but they still had atherosclerosis equal to elderly US men. "The coronary arteries showed intimal thickening by atherosclerosis which equaled that of old U.S. men." (1). The Masai had a high saturated fat, high cholesterol diet.

So we see 2 examples here, where being very lean, while extremely beneficial and healthful, does not counteract a high fat diet.

Best regards, EngineerGuy

(1) Dr. Mann's definitive study in 1971 http://aje.oxfordjournals.org/cgi/content/abstract/95/1/26
 
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Heretk responded:
This is completely overblown! An effect of insulin resistance while eating high fat low carb is temporary and quickly reversible upon resumption of carbs. You don't need to be insulin-sensitive while eating fat! It is a normal physiological reaction! See this study:

http://www.ncbi.nlm.nih.gov/pubmed/20427477

Discussion of this issue:

http://high-fat-nutrition.blogspot.ca/2013/09/axen-and-axen-tradition-continues.html

Quote:

Finally, returning to a chow diet rapidly reversed the effects of KD on insulin sensitivity and glucose tolerance. These data suggest that maintenance on KD negatively affects glucose homeostasis, an effect that is rapidly reversed upon cessation of the diet.


If you or some authors exaggerate some benign irrelevant effect portraying it as supposedly harmful, you will be hurting yourself and those who believe you by excluding a viable nutrition scheme. 10 years ago, when low carb diets were very rare, nutrition "experts" like Ornish et al were trying to scare people about ketone bodies in urine and bad breath. Those like him and others are inventing more and more bogus issues to scare people, while the others are wasting their time having to debunk that kind of nonsense all the time! What else are they going to invent?
H.
 
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engineerguy replied to Heretk's response:
Hi Heretic,

Re: "10 years ago, when low carb diets were very rare..."

No, Dr. Atkins published his first book in 1972. We were around then, and Atkins was very well known. I think the Atkins Diet has always had the highest popularity and name recognition of any diet, because it let people eat what most people want most, meat and cheese, and because some people lose weight very easily on the ketogenic diet. For these people, on ketosis, they are satisfied on 600 calories a day.

Every diet has the issue of regaining the weight. You would think that because many people frequently lose 60 pounds and more on Atkins, that the diet would be very successful. Actually no. The Atkins diet appears to be the worst, for regaining weight. (Jimmy Moore? And, who would have more motivation than a diet guru !!!) Talking to one woman at a TOPS group meeting (Take Pounds Off Sensibly), she said she was the TOPS state queen one year. I hoped I didn't roll my eyes visibly, because she was huge. She said, yes, she regained all the weight and more. The National Weight Control Registry reports that, of their successful weight loss members, only 1% used a high protein Atkins style diet. (People who have lost 30 pound or more, and kept it off for at least a year, with a doctor's note, are encouraged to share how they did it.) Most successful people used their own program of low fat diet, with exercise.

Years ago, I recounted this discussion, and H responded that you have to stay on the diet. This means that we agreed on the first sentence "Every diet has the issue of regaining the weight." I guess H conceded the point about Atkins being the worst diet, in this regard.

Re: "If you or some authors exaggerate some benign irrelevant effect portraying it as supposedly harmful, you will be hurting yourself and those who believe you by excluding a viable nutrition scheme."

I do not ever recall any data that H's diet was actually beneficial for anyone. As for hurting ourselves by following the diets we follow, there are worlds of data on it's effectiveness, not to mention our own anecdotal reports.

I thought the fact was amazing, that visceral fat was higher on the LC-HF diet, until calories were actually cut to 80% of the normal diet, and at 80% of calories, glucose tolerance was still higher than a normal diet. Heretic's response is only that it wasn't so bad. HEY EVERYONE. LET'S EAT THIS DIET. IT ISN'T SO BAD!! The harm is only temporary, and you can quickly recover, according to my theories. Never mind the terrible results of the Masai.

Best regards, EngineerGuy
 
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engineerguy replied to engineerguy's response:
Hi H,

Sorry to come down on you so hard. Don't forget, you did say our program was harmful, which is just egregious. It is unscientific. If you could provide data that a ketogenic program is healthful, that would be very interesting. Skip the data about refractory juvenile epileptic patients (epileptics that do not respond to any drug therapies). It is clear that those patients use ketogenic diets in spite of the health issues.

Dr. Fuhrman strongly advises people against going below 10% fat, which is where Pritikin and the others advocate people be. Dr. Fuhrman advocates water fasting very strongly. His knowledge of fasting, I believe, has allowed Dr. Fuhrman to significantly improve the other programs (Pritikin, etc). During fasting, especially after the 3rd day, the metabolism shifts to a ketogenic metabolism. I though that if anyone would see value in a ketogenic diet, Dr. Fuhrman would. No, Dr. Fuhrman is very definite and clear, that he strongly advises people against a low carb ketogenic diet.

Just come with data.

Best regards, EngineerGuy
 
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anon43 replied to engineerguy's response:
Don't worry, EG about coming down hard on H. Being very cerebral I am sure it has the same effect on him as water off a duck's back. But be very careful what you say to me because I am dainty and delicate and subject to the vapors. If you are going to post something harsh regarding me remember to first warn me so I can get my smelling salts.

dolores


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