A Carb Fan Gets His Say

A few weeks ago, I wrote a Top of Mind about Gary Taubes' Good Calories, Bad Calories. Now, a professor of kinesiology at U. Va named Glenn Gaesser has responded with his critique, which is below, along with my initial e-mail response. After this and the New York Times' story today showing fat people live longer, I'm as confused as ever, though I still think it makes intuitive sense that the best way to remain lean is to eat as little sugar and white flour as possible.

BTW, this is an e-mail exchange, so please read from the bottom up.

Todd,

I have attached a copy of the article I wrote for JADA. Taubes’ book addresses many diet issues, but the most glaring inaccuracies in my view pertain to the issue carbohydrates and body weight.
For example, if carbohydrates make us fat and sick, as Taubes claims, then there should be virtually unassailable evidence to support his thesis. There is not. In fact, with regard to diet, body weight and obesity, there is compelling evidence to suggest that the truth is entirely opposite to what Taubes contends. Among the key findings in my JADA review:
(1) Virtually every major epidemiologic study shows an inverse relationship between carbohydrate intake and BMI. Potential confounders, such as energy intake, smoking, and physical activity, do not appear to undermine this relationship.
(2) The majority of epidemiologic studies also show that glycemic load is inversely related to body mass index;
(3) As for glycemic index (GI), most studies show either no relationship or an inverse relationship between GI and BMI. Several large cohort studies, including the Nurses’ Health Study II, the Women’s Health Study, and the Health Professionals Follow-up Study, revealed that higher-GI diets were associated with lower BMIs. Far from being a contributing cause of obesity, these studies actually suggest that high-GI diets may better for weight control. Although epidemiologic studies cannot prove cause-effect, at the very least these findings need to be addressed with regard to the underlying carb-obesity link. Taubes does not discuss or mention a single one of these studies.
(4) The epidemiological findings are consistent with a large number of interventions studies showing modest “spontaneous” weight loss with non-energy-restricted low-fat diets. I could not find a single study in the literature that showed that non-energy-restricted low-fat diets lead to weight gain, no matter how long the intervention. For example, in the CARMEN trial (Am J Clin Nutr, 2002; 75: 11-20), 6 months of non-energy-restricted consumption of a diet that required the subjects to replace 25% of the fat calories in the diet with simple carbs (which, according to Taubes’ hypothesis, should have resulted in weight gain), subjects’ weights remained constant over the 6 months. When the fat was replaced with complex carbs, the subjects lost about 9 pounds during the 6 months (even though the subjects were instructed not to actively try to lose weight). A number of similarly designed studies (brieftly described in my review in JADA), show the same thing.
(5) While whole-grain intake is associated with lower BMIs, refined grain intake is not consistently linked to higher BMIs.

A recent study published on PLOS Medicine (www.plosmedicine.org; August 2007, vol 4) on a combined analysis of the both Nurses’ Health Studies revealed that the nurses with the highest glycemic load had the lowest BMIs. They also had the lowest risk of diabetes. These results obviously fly in the face of the carbophobic view that high-glycemic load diets cause obesity and diabetes. The most likely explanation for these findings is that the nurses with the highest glycemic load consumed 8-10 times as much whole grains as the nurses with the lowest glycemic load. This also suggests that judging a diet solely on the basis of its carbohydrate content or glycemic properties is not justified.

If sugar is as bad as Taubes contends, how does he explain the data from the National Health and Nutrition Examination Survey, which shows an inverse relationship between sugar intake and BMI? (see Am J Clin Nutr 2003; 77: 1426-1433). The high sugar intake did not appear to adversely affect glucose and insulin because the high-sugar consumers had the same average fasting glucose and insulin as low-sugar consumers, and C-Peptide concentrations (an index of insulin secretion) were actually lower in the high-carb/high-sugar consumers. These NHANES data are consistent with the findings of most epidemiologic studies–sugar consumption is generally associated with lower body weights. (I am not advocating loading up on sugar, but rather just pointing out research findings that do not support the hypothesis that sugar consumption is tightly linked to obesity.)

As for the carb-disease connection, the published data are mixed. Some studies show a link between carb intake and/or glycemic properties of the diet and incidence rates for vascular disease diabetes. Many studies, by contrast show no relationship (some of this is discussed in my JADA review). And, with few exceptions, the vast majority of studies show no link between the glycemic properties of the diet and cancer. In fact high-carb diets that are rich in whole grains have been reported to be associated with reduced risk of several chronic disease, most notably vascular disease and diabetes. This beneficial effect of whole grains (cereal fiber seems to be the key link) appears to be independent of the glycemic properties of the diet. (See Am J Clin 2004; 80: 348-356, for example, and the JADA review, mentioned above, for discussion.)

In the Epilogue of his book Taubes concludes that “certain conclusions seem inescapable” to him. Among them is the assertion that “the fewer carbohydrates we consume, the leaner we will be.” This conclusion has little scientific support. Based on the bulk of published evidence, the opposite appears to be the case.

Best regards,

Glenn A. Gaesser, Ph.D.
Professor and Director
Kinesiology Program
University of Virginia
210 Emmet St., So.
PO Box 400407
Charlottesville, VA 22904
Phone: 434-924-3543
Fax: 434-924-1389
email: gag2q@virginia.edu


From: Wasserman Todd [mailto:twasserman@brandweek.com]
Sent: Tuesday, November 06, 2007 3:31 PM
To: Gaesser, Glenn A *HS
Subject: Re: Good Calories Bad Calories

Dear Glenn:

Thanks for the note. Since I’m a magazine editor and you are a professor of kinesiology, I’m inclined to defer to your judgment, but that would be easier if you provided proof. What facts, in particular, did Mr. Taubes get wrong?
Can you send your recent article?

Thanks.

-Todd

On 11/6/07 2:55 PM, "Gaesser, Glenn A *HS" wrote:
November 6, 2007


Mr. Todd Wasserman
Editor
Brandweek
770 Broadway, Fl 7
New York, NY 10003

Dear Todd:

I am writing in response to your article about Gary Taubes new book, Good Calories, Bad Calories in the October 22, 2007 edition of Brandweek. You wrote that the book provides “enough data to support the hypothesis that what’s really making Americans fatter is not fat, but rather carbohydrates in the form of pasta, bread, sugar and all those other goodies long ago deemed ‘fattening’.”

For the record, Mr. Taubes has his facts wrong. There are volumes of scientific evidence that suggests far from being the “food of the devil,” high-carb diets are generally associated with higher diet quality, better weight control and reduced risk of degenerative diseases. In fact, my recent article published in the October issue of the Journal of the American Dietetic Association discusses how the government’s ongoing NHANES studies show that people who consume the highest percentage of carbohydrates have the lowest BMI, as well as having similar levels of blood glucose and insulin as compared to their counterparts who consume few carbs.

A balanced diet that incorporates all food groups – including grains – is optimum to maintain a healthy weight and deliver vitamins and nutrients to the body. It is also important to note that the 2005 Dietary Guidelines recommend at least half of all grain products consumed should be whole grain products and the remaining from other grain sources, including enriched. In fact, folic acid is added to enriched bread at twice the amount of that found in whole grains.

Contrary to popular belief, bread and carbohydrates—even those with a high glycemic index--can have health benefits. Eating in moderation, in combination with regular physical activity are the most important things when maintaining health – not cutting out specific foods. His stance on exercise is ludicrous as has been proven by numerous scientific studies which he seems to have completely ignored.

Please let me know if you have questions or would like more data or clinical studies.

Sincerely,

Glenn A. Gaesser, Ph.D.
Professor and Director
Kinesiology Program
University of Virginia
210 Emmet St., So.
PO Box 400407
Charlottesville, VA 22904
Phone: 434-924-3543
Fax: 434-924-1389
email: gag2q@virginia.edu

Comments

[Charles (CJ) Hunt]

uh.. this guy is the co-chair of the Grain Foods Foundation, and also does paid research for the Wheat Foods Council.
Why doesn't he disclose these affiliations anywhere in his signature (like his Phd) or emails?? (See GFF's website description below.)

So much for credibility.

Sincerely,
Charles (CJ) Hunt
Investigative Documentary Filmmaker
Current Project: In Search of The Perfect Human Diet
www.CJH3Productions.com

"The Grain Foods Foundation, a joint venture of members of the milling and baking industries formed in 2004, is dedicated to advancing the public's understanding of the beneficial role grain-based foods play in the human diet. ...With a rallying cry of "Bread. It's Essential," this Foundation is committed to programming that is deeply rooted in the science and is working together with the Grain Foods Foundation Advisory Board, a multidisciplinary cross-section of nationally recognized nutrition and healthcare experts, to ensure this benchmark is met every step of the way. "

"Directed by a board of trustees, funding for the Foundation is provided through voluntary donations from private grain-based food companies and is supplemented by industry associations..."

[Dale Matsis]

Wow. Eerie coincidence. A similar "conversation" recently brought this Europe-in-wartime study to my attention:
http://books.google.com/books?id=EPB0rdl0yZQC&pg=PA142&lpg=PA142&dq=norway+drop+in+coronary+disease+in+world+war+ii&source=web&ots=hpQLTP5uEP&sig=OBjjpSHLXvAqc7nr62iSojZtU7E

And simultaneously I was reading about the Oslo Wartime Coronary Disease Study. I'll quote: "The Norwegian diet, traditionally high in beef, grains, and dairy products, became one of near starvation during the brutal Nazi occupation. Ironically, and despite the horrendous stress of the time, the incidence of acute coronary disease plunged, only to rise again to its pre-war level after the war..."

The author also discusses the plunge of Londoners' heart disease during the Blitz, when there was little food. After the war, same as Oslo. Heart disease spiked.

That second quote is from the "Amazing Epidemiology" section, starting on p. 35, of "The Cardiologist's Wife's Chocolate too! diet."
http://www.amazon.com/gp/product/1419673637/ref=cm_cmu_up_thanks_hdr/002-5554450-6716069
The authors point out that unsweetened cocoa is a blockbuster drug. Apparently researchers haven't been this excited about a discovery since the Salk vaccine. Here's Harvard's research:
http://www.GOOGLE.COM/search?hl=en&ie=ISO-8859-1&q=hollenberg+and+the+Kuna+Indians&btnG=Google+Search

[Robert Schneider, M.D.]

I'm and Internist and Cardiologist with over 30 years clinical experience, and a Consultant to the CT Dept. of Public Health. Fourteen months ago, my wife, a heart smart cook, and I became alarmed about the obesity epidemic, and wrote a health and diet book emphasizing the healing powers of cocoa.

Now we're alarmed by this Eat Fat book.

Here's why that book only adds to people's confusion: BOTH fat and carbs in excess are the problem, causing overweight, obesity, and disease. AND -- hello? -- carbs metabolize into fat anyway.

Surprised? Here's how it works: Our metabolism's Houston Control is the liver, which turns carbs first into sugar for fuel, and then turns excess sugar into fat. So even "good carbs" still metabolize (maybe an hour later) to sugar, which, if there's too much, converts into fat.

So eat more fat, and you're doubling, quadrupling the problem. Have any of these science writers ever seen an autopsy? A fatty liver is revolting to look at: yellow, greasy, & floppy instead of firm and reddish-brown. Fat, whether ingested up front Atkins style or metabolized within hours from carbs, IS a main cause of obesity, diabetes, and coronary disease progression.

For half a century, MD's, on the basis of following patients for decades, hands-on clinical experience and huge well-controlled scientific studies, have recognized that this artery damage results from multiple factors including both carbohydrates and fat. It is a huge error, potentially very damaging to the most vulnerable population, the overweight and obese, diabetic and hypertensive, to deny the destructive role of ingesting fat.

Metabolism's bottom line: EVERYTHING we eat metabolizes into one of three things: Protein, fat, or sugar. And excess sugar becomes fat. And that hardening yellow cottage cheese lining your arteries is fat!

It's downright harmful to tell confused people to eat more of the damn stuff.

Sincerely,

Robert G. Schneider, M.D.

[Dr. Terry Swanson]

I have read Good Calories and Bad Calories (GCBC) and many critiques of the book. It is interesting that when people are asked for details or research about what is wrong with Taubes' investigation I do not find anyone interacting with the research he presents. The critiques presented seem to be more opinion based and no research is referenced of documented scientific research programs specifically focused on the key premises being argued. In contrast, GCBC is a compendium of documented scientific research that has been extracted from Journals like JAMA, American Journal of Medicine, etc..

One example of this is the information Taubes presents on the correlations between LDL, VLDL, HDL and Triglycerides with coronary heart disease. Taubes references numerous articles among which are: Research by, Drs. Albrink, Peters, etc. in "Relationships between Serum Lipids and Vascular Complications of Diabetes," in the Transactions of the Assos. of American Physicians, 75:235-41, in which scientific research was performed that revealed Triglycerides and not LDL, have a high correlation with heart disease. This research was again confirmed by Kuo, P.T., in "Hyperglyceridemia in Coronary Artery Disease" and again by Gordon, T., et.al., 1977 in “High Density Lipoprotein as a protective factor against Coronary Heart Disease, American Journal of Medicine, May: 62(5):707-14. This research shows that Triglycerides and not LDL are correlated to coronary heart disease. Taubes also presents additional research that shows Triglycerides are generated from the intake of carbs. I find it very hard to argue with this research and maybe that is why I have never read any critiques of GCBC that use actual scientific studies, or interact with the results of the studies in this example, to prove their arguments. If Taubes' conclusions are wrong, then there must be actual research results which proves the above documented research is flawed.

In GCBC Taubes is drawing from research. In my opinion, his critiques need to interact with the research sources Taubes' quotes and justify their arguments by using specific focused research, not research that is based on assumptions that have not been validated, which shows where the research Taubes bases his conclusions on are flawed. Until this happens the critiques I have read are just someones opinion versus the actual results of research programs.

When reading GCBC I did NOT find it preaching for people to go out and eat all the fat they want. It did not even come off as a diet book to me. If anything it was more of a compendium of research results. One of the key themes I found running throughout the research presented in GCBC was that much of the disease people get is due to insulin resistance, how it is influenced by diet and how so many more people are becoming diabetics and at younger ages.