Interesting Information: “A reversal on carbs”

Interesting Information:  March 27, 2011

“A reversal on carbs”

“A growing number of top nutritional scientists blame excessive carbohydrates–not fat–for America’s ills.”

Walter Willet, chairman of the department of nutrition at the Harvard School of Public Health:  ” `If Americans could eliminate sugary beverages, potatoes, white bread, pasta, white rice and sugary snacks, we would wipe out almost all the problems we have with weight and diabetes and other metabolic diseases.’ “

Dr. Edward Saltzman, associate professor of nutrition and medicine at Tufts University:  “`Now a growing and convincing body of science is pointing the finger at carbs, especially those containing refined flour and sugar.'”

Dr. Frank Hu, professor of nutrition and epidemiology at the Harvard School of Public Health:  “`The overemphasis on reducing fat caused the consumption of carbohydrates and sugar in our diets to soar.  That shift may be linked to the biggest health problems in America today.’ “

Dr. Stephen Phinney, nutritional biochemist and emeritus professor of University of California, Davis, who has studied carbohydrates for 30 years:  ” `However, over time, as our bodies get tired of processing high load of carbs, which evolution didn’t prepare us for…how the body responds to insulin can change.’ ”  Phinney did a 12-week study in 2008 that compared low-fat and low-carb diets.  The low-carb diet lowered triglyceride levels by 50 percent though participants ate 36 grams of saturated fat a day.  (History and evolution show that grain agriculture–in a 24-hour day of human existence–comes in at 23 hours and 53 minutes.)

Dr. Eric Westman, director of the Lifestyle Medicine Clinic at Duke University Medical Center:  “`At my obesity clinic, my default diet for treating obesity, Type 2 diabetes and metabolic syndrome is a low-carb diet.’ “

Naysayers:  Dr. Joanne Slavin, a member of the advisory committee for the failed USDA low-fat diet regime, and Dr. Ronald Krauss, senior scientist at Children’s Hospital Oakland Research Institute and founder and past chair of the American Heart Assn.’s Council on Nutrition, Physical Activity and Metabolism, a believer in the calorie in/calorie out paradigm–which cannot demonstrate success in weight loss because it doesn’t work.  (See Gary Taubes WHY WE GET FAT.)

 Here’s the whole article:  Marni Jameson, “A reversal on carbs,” LA Times, December 20, 2010, http://articles.latimes.com/2010/dec/20/health/la-he-carbs-20101220

Mainely Tipping Points 28: Why We Get Fat

Mainely Tipping Points 28:  WHY WE GET FAT

 

In WHY WE GET FAT (2011), Gary Taubes—a highly respected science researcher and writer, drives a scientific stake into the heart of the “calories in/calories out” paradigm that began developing in the 1950s and grew to become the medical orthodoxy we experience today.  Taubes explains the proven science behind why some people get fat—a question totally lost in the wilderness of the “energy balance” paradigm and its attendant low-fat/high carbohydrate diet.  The circular logic of this paradigm holds overweight people in a vicious, unscientific, damaging, deeply cultural  polarity:   either people of low character eat too much (gluttony) or exercise too little (sloth).  

Taubes traces the history of when research in nutrition and obesity “lost its way” and observes that these fields have “resisted all attempts” at correction.  Much understanding, Taubes writes, was lost after World War II with “the evaporation of the European community of scientists and physicians [particularly the Germans] that did the pioneering work” (ix).  Since that time, writes Taubes, “individuals involved in this research have not only wasted decades of time, effort, and money but have done incalculable damage….Their beliefs have remained impervious to an ever-growing body of evidence that refutes them while being embraced by public-health authorities and translated into precisely the wrong advice about what to eat and, more important, what not to eat if we want to maintain a healthy weight and live a long and healthy life” (ix). 

Taube’s earlier book GOOD CALORIES, BAD CALORIES (2008) is an extended, densely researched book written to start a conversation with “the experts.”  Taubes believes that it might take another lifetime to change this paradigm, but, meanwhile, he sees that the disease burden (obesity, diabetes, heart disease, and cancer) being created by eating the wrong foods is “overwhelming not only hundreds of millions of individuals but our health-care systems…” (x).  Taubes wrote WHY WE GET FAT so the lay person could understand what’s wrong and have the courage to take personal charge of his/her health rather than relying on “some of the misconceptions that pass for public-health and medical advice in this country” (xi).

So, why do some people get fat?  All real food, as compared to some of the chemical brews passed off as food today, is composed of fats, proteins, and/or carbohydrates.  In a nutshell, people have genetic tendencies toward fatness or thinness that combines with a hormonal chemical disorder caused by eating too many carbohydrates—which throws off the body’s ability to regulate fat accumulation appropriately in both fat and thin people. 

Here’s a gross simplification of Taube’s main explanation:  Fat accumulation is regulated by hormones, and the most important hormone is insulin.  Ideally, when our insulin levels are elevated, we accumulate fat in our fat tissue.  When insulin levels fall, fat is liberated from fat tissue and is burned for fuel.  However, easily digestible carbohydrates, like highly processed sugars and grains and starchy vegetables, make the body produce more insulin.  And, this insulin works to trap fat inside fat cells; it does not release them to burn for energy.  Thus, obesity is a hormonal imbalance, not a caloric imbalance.  Worse, this hormonal imbalance makes an overweight person hungrier because the body is growing larger, and it makes that person sedentary because all the food energy is being stored, not burned.  Gluttony and sloth are effects of this hormonal imbalance, not causes (10). 

Insulin, Taubes writes, works also with other hormones, like the sex hormones, and countless enzymes to partition fuel around the body.  This chemical process decides what food energy is burned, what is stored, and in which tissues it is stored (fat, muscle, liver).  An insulin disorder can partition a disproportionate amount of consumed calories into storage as fat, rather than having them used for energy by the muscles.  In lean people, the factors work to burn as fuel a disproportionate share of the consumed calories, which creates high energy levels (128).   

Some people, Taubes explains, develop insulin resistance, which means the body has to secrete higher and higher insulin levels in order to perform the same tasks—a “vicious cycle” intensified by eating easily digestible carbohydrates.  Next, these people start to manifest the precursor to heart disease, metabolic syndrome.  Body fat accumulates, especially around the waist; blood pressure rises; triglycerides levels rise; LDL cholesterol particles become small and dense; HDL cholesterol levels fall; and blood sugar becomes erratic (glucose intolerance).  Diabetes occurs when the pancreas can no longer secrete enough insulin to keep the body balanced.  And Alzheimer’s and most cancers are “associated with metabolic syndrome, obesity and diabetes” (195-198). 

Taubes’ subject is why we get fat, so he does not address the health effects on the lean, energetic person whose leanness is created by this hormonal disorder, which is, in turn, caused by eating too many of the wrong kinds of carbohydrates.  He does note that that as we age, our muscles become increasingly resistant to insulin and more energy gets partitioned into fat (130-131).   

There are generational components to these disorders.  Taubes notes that worldwide studies demonstrate that children born to a mother with hormonal imbalances that have created obesity are likely, also, to struggle with obesity.  The nutrients the mother’s body supplies to her baby affects his/her levels of glucose, which, in turn, affects the pancreas so that it develops more insulin-secreting cells, which, in turn, makes the baby fatter at birth.  These babies have a tendency both to oversecrete insulin and to become insulin-resistant (132).            

Exercise, Taubes demonstrates effectively, will not make one lose weight.  Indeed, for weight loss, exercise is counterproductive because it creates hunger (40-56).  And, undereating  does not work.  At some point one must return to eating normally, and the weight returns.  Taubes reports that the eight-year, billion-dollar National Institutes of Health initiative, the Women’s Health Initiative (WHI) of the 1990s, showed that a low-fat diet did not result in weight loss and “did not prevent heart disease, cancer, or anything else” (33-39). 

Taubes looks at many current studies, among them the 2007, two million dollar, government-funded A TO Z Weight Loss Study from Stanford University which compared four diets:  Atkins (low carbohydrate), LEARN (a traditional diet with 55-60 percent carbohydrates), Ornish (low fat), and the Zone diet.  The Atkins diet won, substantially and significantly, across the measured categories (weight loss, dropping triglyceride levels, dropping blood pressures, and improved cholesterol conditions)—prompting lead researcher Christopher Gardner, a twenty-five year vegetarian, to note that the results were, for him, a “`bitter pill to swallow’” (191-192). 

Taubes notes that Atkins diet participants were allowed to eat as much red meat and meat fat as they wanted (191-192).  And, that “since the 1960s, when it was first argued that animal products could be bad for our health because they contains saturated fat, nutritionists have typically refrained from pointing out that meat contains all the amino acids necessary for life, all the essential fats, and twelve of the thirteen essential vitamins in surprisingly large quantities.”  Meat, writes Taubes, “is a particularly concentrated source of vitamins A and E, and the entire complex of B vitamins.”  Indeed, “vitamins B12 and D are found only in animal products….”(176).

Vitamin C is the “one vitamin that is relatively scarce in animal products.”  But, “the more fattening carbohydrates we consume, the more of these vitamins we need.  We use B vitamins to metabolize glucose in our cells.  So, the more carbohydrates we consume, the more glucose we burn (instead of fatty acids), and the more B vitamins we need from our diets.”  When we eat carbohydrates, we “excrete vitamin C with our urine rather than retaining it” (176). 

Without carbohydrates in the diet, Taubes notes, “there’s every indication that we would get all the vitamin C we ever needed from animal products.”  Thus, Taubes concludes, “Carbohydrates are not required in a healthy human diet.”  And, “another way to say this (as proponents of carbohydrate restriction have) is that there is no such thing as an essential carbohydrate” (176).             

The solution to both obesity and leanness accompanied by excessive energy is actually pretty simple:  stop eating carbohydrates, especially the easily digestible ones, like, bread, pasta, potatoes, sweets, beer, fruit  juices, and sodas.  (I’d add cold breakfast cereals to this list.)  Taubes notes that before the 1960s, conventional wisdom recognized that these foods were “uniquely fattening.”  And, he notes that this message has been at the heart of an “unending string of often best-selling diet books” (11).  He also notes that “when physicians stopped believing it, a process that began in the 1960s and concluded in the late 1970s,” their change coincided “with the beginning of the current epidemics of obesity and diabetes” (150).     

Taubes does note that if the obesity has gone on too long, the body may not be able to reset its own chemistry (205).  And, that if one is taking medications to lower blood sugar or blood pressure, one should work closely with a doctor because following a low-carbohydrate diet lowers both so that a dangerous “double whammy” effect can occur (216). 

Taubes reproduces the Atkins-version diet used by Dr. Eric Westman of the Lifestyle Medicine Clinic at the Duke University Medical Center.  Westman has been working with this diet since 1998 (202).  And, Taubes points to four other doctors with similar clinical practices across the country (202).   

My only critique of this diet is that it allows artificial sweeteners and does not distinguish well between good fats and bad fats.  But, you can read Tipping Points 14 to understand how to sort those fats out for yourself.