Weight loss, but at what cost?

All it takes is a stroll through a grocery store to realize our society has become low-carb crazy. Healthy products targeted towards dieters which were once developed and adverstised as low fat have now been reworked and marketed as the newest low-carb option. Sales of bread, potatoes, rice, and pasta are dwindling as they are being replaced by ever increasing sales of much more expensive dairy products, processed meat snacks such as jerky, and nuts. While the large food manufacturers are watching their bankrolls swell, wheat and potato farmers, as well as small bakeries and pasta manufacturers are going belly-up. True to form, the American public is eager to jump on the quick fix bandwagon and the sales numbers show the increase. In 2004, U.S. consumers are expected to spend an estimated $30 billion on low-carb products, up from $15 billion in 2003.


Despite the popularity of low carbohydrate diets, critics of the low-carb craze -- including most of the medical establishment -- claim the diets are difficult to follow and sustain, nutritionally deficient, and most frightening, medically dangerous.
Besides the most obvious goal of weight loss, proponents of low carbohydrate diets claim many health benefits including increased energy, better digestive function and most commonly raising of HDL, the "good" cholesterol. They point to two recent studies which seems to have proven that obese people can raise their levels of HDL while maintaining the same levels of LDL, the "bad" cholesterol. Two recent studies conducted at Duke University (funded by a vocal proponent of low-carb diets, The Atkins’ Foundation) compared two groups of dieters, one group followed a low carb meal plan, the other a more traditional low fat diet. After six months the low carbohydrate group increased levels of HDL cholesterol by 5.5% while the low fat dieters HDL levels fell 1.6%. While the levels of good cholesterol rose among the low-carb dieters, their LDL levels remained nearly the same. The low-fat group experienced a marked decrease in the LDL levels.


The main reason people follow a low carbohydrate is to lose weight. In his book Dr. Atkins’ New Diet Revolution, Robert Atkins, founder of the Atkins diet, claims that depriving the body of carbohydrates forces the body into a fat burning state called ketosis, as well as diminishment of hunger pangs. Whatever the biological reason, it seems everyone knows someone who has lost weight on a low carb diet such as the Atkins Diet, the Zone, or the South Beach Diet. Even my girlfriend subjected herself to weeks of cheese, mashed cauliflower (Which I assure you, is a sorry substitute for mashed spuds.) and sugar free jello while following the South Beach method, and there is undeniable evidence that followers do lose weight. But at what health cost?
A diet low in fat and cholesterol has generally been accepted as the healthiest approach, even for people not seeking to lose weight. There are many reasons for this, including evidence that such a diet lowers risks serious consequences such as cancer or heart disease. But there are many hidden risks to a high fat and protein diet as well. Elizabeth Poletti, the nutrition manager of Duke University’s Diet and Fitness Center explains,

"We do know that if you eat fewer carbohydrates, you're going to replace them with protein and fat," she says. "And eating a high-protein diet can raise your risk of cancer. There are already some studies that have suggested that. It's definitely not good for your kidneys, because your kidneys are the only organs in your body that can break down and dispose of extra nitrogen from the protein you're eating. If you're also not eating the same amount of carbohydrate as before, you're also probably eating more fat. And we know that a diet high in saturated fats is linked with an increase in heart disease." Her views are echoed by the National Diabetes Association which urges individuals with injured kidneys, as a result of diabetes or other wise, to avoid the excess nitrogen produced a diet excessively rich in protein.


But what of the claims of increased levels of HDL cholesterol when compared to more traditional weight loss diets? It seems that claim is also unsubstantiated. The results of the Duke Univeristy study mentioned above were mixed. Yes, the HDL levels in low-carb dieters increased while LDL levels remained nearly the same as an overall average, but nearly 33% of the participants did in fact, experience an increase in LDL levels. One participant’s levels of LDL spiked so dramatically they were removed from the test and the diet.

During the same study, the individuals who followed a reduced calorie, low fat diet as advocated by medical organizations as the American Heart Association experienced an overall reduction in LDL levels. While the levels of HDL levels present in their blood was lower, the gains achieved by the lowering of LDL was more than enough to offset the lowering of unhealthy cholesterol levels.
It should also be noted that the two recent studies have both been six month studies. Six months is a very short period, especially when diseases such as hearth disease and cancer take years to develop. Doctor Eric Westman of Duke University administered the Atkins’ Foundation funded research projects and admits there may be problems in using such a s short-term study. He explains,
"There are people who have done the diet for years, but not in a large enough number and not with monitoring to know that they're healthy by all of the parameters that we can measure. In both of these studies, I closed up shop after six months and told the patients, 'I'm not even sure you should be on this diet.'" Professor of medicine Howard Eisenson agrees,

"The decent studies on low-carb diets are in their infancy," he says, and he directs those in his care to follow the more traditional low fat approach. "Our low-fat diet has the greatest weight of scientific work behind it. We've been doing it for a long time. We feel most confident in this as a way of life," Eisenson continues.


While the current low carbohydrate fad may in fact be helping many lose weight, it is troubling to think millions are following a diet with little or no long term research into the effects on the body. American’s search for the newest way to lose weight fast may be leading us towards disaster. Remember Phen-phen or ephedra anyone?