Volume 1  Number 6  September 30, 2004
Second Opinions

Weight Loss 101: Diet Fashions and Fallacies (Part I)

A shocker: Last week shares of Interstate Bakeries, the country's largest wholesale baker, makers of Hostess Twinkies and Wonder Bread plunged from $15 to $2.5, following which they filed for Chapter 11 bankruptcy protection. Earnings have slumped at Krispy Kreme Doughnuts, and at Entemann's, a respected supplier of desserts in the Northeast; while other large food and soft drink companies are feeling the wrath of the Al Qaeda of Diet Discourse: Low Carbs.

If you're in the food business in Europe, Research and Markets, of Dublin, Ireland offers you a report in response to the rising levels of obesity, "enabling you to target the booming sectors for low-carb development…" The report "analyses the food and drink products threatened by the low-carb diets and Atkins™ revolution such as: biscuits, bread, rice, potatoes, pasta, breakfast cereals, pastry, pizza,… fruits, sugar, alcohol, caffeine, fruit juice and milk."

Googlizing in my spare time, I got 3.93 million hits on the Internet search term "diets." Wandering further, I retrieved 105,225 books titles on the same term, thanks to Amazon.com. There's the South Beach Diet, The Abs Diet, the Insulin Resistance Diet, and of course thousands of other titles, not to mention books on The Atkins Diet, which have already sold over 45 million copies. None of this is news, of course, in a country, where reportedly 30% of its citizens are overweight, a culture simultaneously obsessed with ethnic restaurants, $5,000 a week fat farms, and liposuctions, and bariatric (intestinal bypass) surgery.

Official Government Language on Fats and Carbs Called Vague and Meaningless

More than 25 nutrition experts recently urged the federal government to revise key nutrition messages proposed in the recent report from the Dietary Guidelines Advisory Committee (DGAC). The nutrition experts said several messages, particularly those advising Americans to choose fats and carbohydrates "wisely for good health," were so vague as to be meaningless. In a letter [PDF] to the Department of Health and Human Services, the experts said that the government should make those messages more specific and understandable.

Meanwhile the USDA uses its Food Pyramid to advise people what to eat and to dictate federal food programs. A few years ago, fats were Out, carbs were In. The department claims that the panel of nutritionists it appointed to create the pyramid delivered top-notch advice. Not everyone agrees. "Too often the panel takes nutrition research out of context or allows financial interests to taint its decisions," says nutritionist Walter Willet, Ph.D., of Harvard School of Public Health. In fact, last year, the USDA lost a lawsuit charging that too many of its panel members have ties to the meat and dairy industries.

The Way We Ate

Our fundamental problem is that we are fighting some 100 million years of genetic adaptation to food scarcity and famine. Until the late stone age, humans were lucky if they ate once every few days. (There is still controversy over the evolution of human diets, whether we started primarily as meat eaters or vegetarians, but clearly our digestive tract suggests that we are adapted as both meat and plant eaters, omnivores. Moreover, our metabolic pathways are adjusted for periods of food deprivation. Near normal blood sugar is maintained scrupulously for 15–30 days during periods of fasting before falling to life-threatening levels.) Not only did we need to work hard in order to gather enough food, but those who accumulated body energy reserves in the form of fat enjoyed a survival advantage in terms of their genetic make-up. We have developed several mechanisms that encourage us to eat, but currently we are able to override innate mechanisms which consistently prevent us from overeating.

Caloric Balance and Weight Changes

The low carbohydrate diet (also, in many senses, a high fat diet), which has been around since the 1860's, has enjoyed an astounding re-awakening in recent years. But if one looks at the history of weight loss diets, other magic methods have recurrently captured the public imagination. So we have had low fat, high protein, low protein, high carb, low carb and other "miraculous" diets. Moreover, every week brings an avalanche of audacious fad diets: the grapefruit diet, the lettuce diet, the banana diet. Where does this leave Low Carbs and Atkins?

Atkins and other diets of shifting composition (altered ratio of the three main foodstuffs, carbohydrate, fat, and protein), if analyzed by calories and in the long run (6–12 months) are consistent with the first law of thermodynamics. This is another way of stating that if we eat food that provides the same amount of energy (calories) we expend, we maintain a constant weight. If we consume fewer calories than we burn, we lose weight. Eating more calories than we burn, we store the extra as fat. Unfortunately, over time, few of us achieve a precise balance of calories in and calories out. To be out of balance by only forty Calories a day, energy expenditure included, one extra apple means that we can gain on a two thousand Calorie intake three pounds a year, thirty pounds in a decade. No wonder losing weight is such a notoriously difficult achievement. If this were not so, the current first world epidemic of excess weight and its associated illnesses would have been conquered by now. Not only is the obesity epidemic rampant, but the proportion of the population carrying excess weight is still rising. Even more important, the age at which the problem starts is decreasing steadily.

Bottom Line: Does the Atkins Diet Really Work?

Stay Tuned for the Next newsletter.

Martin F. Sturman, MD, FACP

Copyright 2004, Mathemedics, Inc.

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