Wednesday, June 29, 2011

Smackdowns Galore

Pity the proponents of high-carb diets and calorie restriction. They've had the roughest week since Denise Minger dismantled the China Study.

First, Jimmy Moore of the Livin' la Vida Low Carb blog dropped the bombshell that a member of the 2010 Dietary Guidelines Committee (U.S.) publicly stated that there was no scientific basis for the U.S. dietary guidelines. Excerpt below--see Jimmy's blog for the whole jaw-dropping scoop.

Joanne Slavin, PhD, RD, professor of Food Science and Nutrition at the University of Minnesota, was the head of the Carbohydrate Committee and on the Protein sub-committee for the 2010 Dietary Guidelines Scientific Advisory Committee. She was invited to be one of the guest speakers at The 9th Conference on Preventative Nutrition in Tel Aviv, Israel on May 18, 2011. Perhaps Ms. Slavin felt more at liberty to express her true feelings about the final version of the 2010 Dietary Guidelines being overseas and didn’t realize that I’d have eyes and ears listening in to what she had to say. But according to my source [Miki Ben Dor] who was in attendance to hear her speech, you could tell she had an obvious discontent with the nutritional recommendations that are now being thrust upon Americans.

"There is no scientific basis for the U.S. Dietary Guidelines."

Yes, you read that right! Although Slavin was a major part of the scientific panel that went into creating the nutritional recommendations that will become the standard for what constitutes a “healthy” diet for the next five years, she feels the final version was not based on that science. My source noted that she described the review process where members of the 2010 Dietary Guidelines Scientific Advisory Committee were asked to base all of their recommendations on the scientific evidence specifically related to humans, especially intervention studies. However, there was only one problem with that according to Slavin.

"There are no human intervention studies."

She explained that in the end the Committee had to rely primarily on prospective cohort studies or “expert opinion” which my source said she dismissed as inferior from a scientific point of view. My source said members of the audience were “flabbergasted” to hear such a prominent member of the 2010 Dietary Guidelines Scientific Advisory Committee basically dismissing the recommendations that were revealed on January 31, 2011.

Next, well-known author and researcher Jenny Ruhl, who writes the Diabetes Update blog, smacked down the 600-calorie-per-day diet that supposedly "cures" diabetes 2 as "idiotically dangerous." (My post on a Ancel Keys's year-long experiment of a low-calorie diet and comparison to modern diet plans is here.) Excerpt below.

There's no mystery here, nor is the effect reported a result of "reducing fat in the pancreas" as the doctor who came up with this "cure" suggests. All he has done is craft a "balanced" diet that has so few calories it is also low in carbohydrates.

...because of [doctors'] fat phobia, the only way doctors can feel comfortable prescribing a very low carb diet is by pretending they aren't prescribing one--which they do by prescribing "balanced" diets, one like the one reported here, where the calories are so low that a diet that includes 33% of calories in the form of carbohydrate becomes a low carb diet.

In fact, there's nothing new or healthy about the low cal diet this doctor has come up with. The starvation diet is well understood--and very expensive. It can only be pursued under the supervision of paid medical staff that includes trained nutritionists because cutting calories that low on your own can be extremely dangerous both to your body and your mind.

The classic research on ultra low calorie diets, the starvation research conducted by Dr. Ancel Keys during WWII showed that people eating very low calorie diets developed psychoses (i.e. severe mental illness) at a surprisingly high rate, as well as many other important health problems. Poorly crafted medically supervised low fat starvation diets have caused deaths in the past.

Jenny also cites some of the failures of gastric bypass surgery and commercial interests in the medical industry, plus achieving good blood sugar control with a low carb diet, in the same post. I know from watching my mother that whacking out carbs helps tremendously in controlling blood sugar.

Finally, Dr. Richard Feinman gives a big thumbs down to a paper stating that there's no advantage of a high protein diet v. a high carb diet in managing diabetes:
The paper by Larsen, et al. [1] represents a kind of classic example of the numerous studies in the literature whose goal is to discourage people with diabetes from trying a diet based on carbohydrate restriction, despite its intuitive sense (diabetes is a disease of carbohydrate intolerance) and despite its established efficacy and foundations in basic biochemistry. The paper is characterized by blatant bias, poor experimental design and mind-numbing statistics rather than clear graphic presentation of the data. I usually try to take a collegial approach in these things but this article does have a unique and surprising feature, a “smoking gun” that suggests that the authors were actually aware of the correct way to perform the experiment or at least to report the data.


One strategy is to take advantage of the lack of formal definitions of low-carbohydrate diets to set up a straw man. The trick is to test a moderately high carbohydrate diet and show that, on average, as here, there is no difference in hemoglobin A1c, triglycerides and total cholesterol, etc. when compared to a higher carbohydrate diet as control – the implication is that in a draw, the higher carbohydrate diet wins. So, Larsen’s low carbohydrate diet contains 40 % of energy as carbohydrate. Now, none of the researchers who have demonstrated the potential of carbohydrate restriction would consider 40% carbohydrate, as used in this study, to be a low-carbohydrate diet. In fact, 40% is close to what the American population consumed before the epidemic of obesity and diabetes. Were we all on a low carbohydrate diet before Ancel Keys?

(After Ancel Keys finished the starvation experiment, he went on to develop the lipid hypothesis and started the low-fat diet curse.) Unlike most academic papers, Dr. Feinman's whole post is in plain English, making it easy to relish. The whole article is full of goodies like the ones quoted. (Hat tip to the Fat Head blog for bringing Dr. Feinman's post to my attention. In fact, if you liked my post, you'll love the Fat Head blog--Tom Naughton does posts like the ones I quoted all the time.)

Executive Summary

Got diabetes? Or just wonky blood sugar? Think starving yourself is a good way to lose weight? Just whack the carbs way down and ignore the food pyramid.

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