A Low-Carb Shell Game
By Michele Bloomquist
Jan. 1, 2001 -- Eggs and bacon for breakfast, tuna fish with mayonnaise -- hold the bread -- for lunch, two hard-boiled eggs for a snack, and a big T-bone steak for dinner. That's a typical meal plan for 27-year-old Stacy Smith, a recent convert to the fad of the moment: the low-carbohydrate diet.
The Portland, Ore., resident can eat unlimited amounts of meats and cheeses and other dairy foods, but few vegetables, and no fruits or grains.
It's almost too easy. No calorie counting. No portion sizes. Just avoid the "bad" foods, which in this case include things like pasta, bread, apples, and pears.
The plan, which proponents say has been adopted by more than 10 million people since the book Dr. Atkins New Diet Revolution first was published in the 1970s and republished in the late 1990s, flies in the face of conventional advice about calorie reduction and balanced nutrition. Copycat plans like Sugar Busters and The Carbohydrate Addict's Diet follow similar principles. By limiting the intake of carbohydrates, the theory goes, the body is forced to turn to stored fuel -- in other words, fat -- into energy, entering a fat-burning state called ketosis.
Not everyone is convinced, however. Opponents say that restricting carbohydrate intake isn't a magic formula for fat loss, feeling instead that these plans may leave you lighter in weight but with just as much body fat.
The Low-Carb Shell Game
How can a diet make you lose pounds but not fat? It's all in the way low carbohydrate diets work, says Karin Kratina, MA, RD, a nutrition therapist who specializes in treating weight and eating problems in her private practice located in Gainesville, Fla. She tells WebMD that carbohydrates are broken down into glucose by the body, which in turn either is used immediately for energy or converted into a storage form called glycogen, primarily in the cells of the liver and muscle. Such glycogen is metabolized easily back to glucose, and provides about half of the body's energy supplies daily. Everything from processing a thought to getting from point A to point B requires energy from glycogen, Kratina says.
"At any [given] time, we have about 1,200 calories of glycogen on board," she says. And for every gram of glycogen stored, so are three grams of water. Therefore, when carbohydrate intake is restricted and the existing stores of glycogen stores are exhausted, the body sheds the stored water, leading to an impressive water "weight loss" within a few weeks.
Once the glycogen is gone, the body does turn to fat as a fuel source. But in reality, fat is an inferior energy source compared to glycogen. It's like trying to run a car on lighter fluid, says John Acquaviva, PhD, assistant professor of physical education at Roanoke College in Salem, Va. "In ketosis, the body does burn a higher percentage of fat, but overall, less calories are burned," he tells WebMD.
"People need to remember that there are a lot of ways to lose weight, but not all of them are healthy," Acquaviva says. "Starvation is one obvious example." As the body starts to burn stored fat, it creates byproducts called ketones, leading to the state of ketosis.
If the determined dieter sticks to the plan despite the unpleasant side effects of this state -- including foul acidic breath, fuzzy thinking, and fatigue -- additional pounds will come off. But like the water loss, it is an illusion. The majority of the loss is muscle, not fat, leaving the dieter with a higher body fat percentage and less lean muscle tissue, Kratina says.
Then the carbohydrate cravings kick in, she says. The body seeks to replace the missing glycogen and restore balance. Dieter Stacy Smith knows this feeling all too well.
"I'll suddenly crave things like bread, oatmeal, ice cream," she says. "I'll binge, eating three or four bowls of oatmeal at a time." When she does, her body once again stores glycogen and water, leading to a dramatic "weight" gain. The numbers on the scale quickly rise 10 to 15 pounds, reinforcing the idea that carbohydrates are to blame.
Smith accepts the label of carbohydrate "addict" and goes back on the plan. It becomes a vicious circle of starve, binge, starve, binge.
Breaking the Cycle
The key to ending this eating pattern, says Gail Frank, PhD, a professor of nutrition at California State University in Long Beach and a spokeswoman for the American Dietetic Association, is to realize that carbohydrates aren't the problem any more than are fats or proteins. "Carbohydrates aren't bad," she says. "It's the way people eat too much of them that's bad. People need to put less blame on the food, and more responsibility on the fingers that put the food in the mouth, and the human mind that decides to eat too much."
The low-carb plans also fail to address some of the reasons many people are overweight in the first place, says Frank. They don't teach healthier behavior -- such as learning to recognize a reasonable portion size or examining the emotional reasons why a person may be overeating. What's more, she says, the plan just isn't sustainable. "You can only eat hamburger without the bun for so long before tiring of it," she says.
Glenn A. Gaesser, PhD, agrees. A professor of exercise physiology at the University of Virginia in Charlottesville, Gaesser published a book in 1996 titled Big Fat Lies: The Truth About Your Weight and Your Health. He says many dieters are dieting to get thin, not healthy. "These plans sound sexy: You can eat all the bacon and eggs and steak that you want," he says. But that isn't a healthy way to live or eat.
The Non-Diet Plan
Gaesser encourages people to reject the message that "thin equals healthy" and instead to embrace their genetic body shape. "Some people are tall, some short. Some thin, some fat," he says. "People have to be realistic about what body weight they can actually achieve.
"If you look at the scientific evidence, it suggests that if you want a good, healthy body that works well for a long time, you'll find that more often than not, it is to your advantage to have a high dietary fiber intake, a reduction in saturated fats, and regular exercise of 30 minutes most days of the week."
Follow these guidelines, says Gaesser, and your health and weight will naturally stabilize at their optimal levels.
After hearing the arguments against low-carb diets, Smith reconsidered her decision. "I'm going to follow a balanced eating program and start walking 30 minutes a day," she says. "I'm tired of up and down and up and down. I want something that will work for life, even if it takes a little longer to get there."
Michele Bloomquist is a freelance writer based in Brush Prairie, Wash. She writes frequently about consumer health.
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