Big Fat Lies and Carb Calumny
Jacob Sullum | October 12, 2007, 12:23pm
In his New York Times science column this week, John Tierney takes on the idea that calories from fat are especially bad for you. Gram for gram, fat does provide more calories than protein or carbohydrates do. But critics of low-fat diet advice have long argued that total calories are what matters for people concerned about their weight, and that overemphasizing fat reduction can actually encourage overeating (as when people gorge themselves on "low-fat" snacks that have about the same calorie content as the standard versions). In his book Good Calories, Bad Calories (which Tierney has read but I have not), science writer Gary Taubes goes further, questioning the conventional wisdom that fat consumption contributes to heart disease. Tierney agrees with Taubes (who is famous/notorious for his 2002 New York Times Magazine cover story suggesting that high-fat, low-carb guru Robert Atkins was onto something) that physicians rushed to judgment about the cardiovascular impact of fat consumption. Tierney describes the anti-fat consensus as the result of an erroneous "informational cascade," in which a few prominent endorsements triggered an avalanche of authoritative statements with little scientific basis.
Tierney is not so sure about Taubes' attempt to vilify carbs instead of fat, and I share his skepticism. Are we condemned to forever swing between these two extremes of nutritional wisdom? Is it possible that the boring old advice about a balanced, omnivorous diet is closer to the truth after all? Or maybe it's just the safest course in the face of uncertainty.
Michael Fumento attacked Taubes' New York Times Magazine piece in the March 2003 issue of reason. Here is Taubes' response and Fumento's reaction to it.
kevin m. | October 12, 2007, 9:21pm | #
Total cholesterol levels have no impact on heart health - what is dangerous is triglycerides. A low-carb diet commonly reduces triglycerides up to 75% within a matter of days. There are two books on the cholesterol myth with the exact same name: "The Great Cholesterol Con", one by Anthony Colpo and one by Dr. Malcolm McKendrick. These can answer your questions about the evidence exonerating dietary cholesterol.
The body does not "need" glucose from carbs, it can happily derive glucose from protein (gluconeogensis), but the body also runs perfectly well on ketones, which are the product of metabolized fat. Fat is merely stored excess glucose, and this storage process of glucose is controlled by Insulin. (The body does not store excess generic calories as fat, it only stores glucose which mostly comes from carbs). Ketosis is the perfectly normal process of metabolizing this fat for fuel, and lowering carbohydrate intake to 20 grams daily puts the body automatically into this fat-burning state, without any additional need for counting or lowering of calories. Caloric lowering does not have any effect of inducing ketosis.
This is how dietary metabolism works, a dynamic completely missed by most researchers of the last 70 years, and most recently re-discovered and expressed by Dr. Atkins, though it has been known since the 1860's.
Different types of calories are not metabolized the same, therefore they are in no way equivalent to the body, another science myth. It is common among low-carbers to increase caloric intake while continuing to lose weight. Low-calorie "starvation diets" simply deprive the body of all nutrition, while low-carb is a "nutrient dense" diet, which maximizes caloric nutrition. Keto-acidosis is the unhealthy process of metabolizing one's own muscle as a result of starvation dieting. This has no relation to ketosis.
Americans never had a high-fat diet, a third science myth. The incidence of heart disease, weight gain and diabetes exactly matches the addition of highly refined carbohydrate into the US diet over the last century, and spiking after 1970 with the introduction of corn syrup into many foods. Every single symptom of Metabolic Syndrome is reversed by a low-carb diet (for level-one evidence of this see Volek and Feinman report below). This should be evidence enough to demonstrate an extremely strong correlation between our great "mystery epidemics" and dietary carbohydrate. No such correlation exists for dietary fat.
In other words, overweight, diabetes, hypertension and high cholesterol are all merely symptoms of ONE disease, and their cause is not caloric, but metabolic. Dietary calories have little direct correlative effect on metabolism, but dietary carbs have a very direct correlative effect.
Read Taubes' book if you want to see evidence for all of this, he's not making any unsupported claims. For that matter, read Atkins' book. Also see "Men's Health TNT Diet" by Adam Campbell and Jeff Volek, a leading low-carb researcher, for some very compelling recent research. In the end, these writers and researchers are touting low-carb because it frequently works, and dramatically well, where low-fat and low-cal have largely failed. If low fat was true, then we all would have attained perfect health over 30 years ago - instead we are all far sicker. Considering this, low-carb is just asking for equal time, credit and funding in the laboratory, at the very least.
For more information online, see:
http://www.weightoftheevidence.blogspot.com (Regina Wilshire)
http://rjr10036.typepad.com/askdrvernon/ (Dr. Mary Vernon)
http://www.proteinpower.com (Drs. Michael and Mary Dan Eades)
http://www.diabetes-normalsugars.com (Dr. Richard Bernstein)
http://www.dsolve.com
Dr. Ron Rosedale on the role of Insulin in dietary metabolism:
http://drbass.com/rosedale2.html
Volek and Feinman comprehensive review of carb-restriction studies (2005):
http://weightoftheevidence.blogspot.com/2006/04/level-one-evidence-to-treat-metabolic.html