Low-carb diets compromise overall health, nutritionist says

Monday, September 27, 2004

Low-carbohydrate diets have become extremely popular, with many restaurants, food brands and soft-drink companies catering to it.

But according to nutritionist Juliet Getty, a University of North Texas faculty member, a low-carb diet isn't healthy because it trades off balanced meals for fats from animal sources as well as foods that are high in protein. Consequently, the body can be starved of needed nutrients, she says.

"People lose weight rapidly on the diet because the body is forced to break down its own muscle tissue for glucose production. Glucose is the source of energy for the brain," Getty says. "When you lose muscle, you lose a lot of weight. The same volume of muscle is heavier than fat, so you become lighter quicker."

The downside to this method is that your metabolic rate significantly slows, so that once you go off the diet and eat balanced meals, you easily regain the weight, she adds.

Low-carb diets also cause people to go into a condition called ketosis, in which the ketone levels in the blood increase. Elevated ketones in the blood reduce appetite, but also lead to risky changes in blood pH and even comas, Getty says.

"Foods high in carbohydrates, especially legumes, vegetables, fruits and whole-grain foods, provide valuable fiber, vitamins and other phytochemicals," she says. "Diets that exclude them can put people at an increased level of risk toward developing major killer diseases, such as cancer and heart disease."

The risk of developing these diseases increases when a person increases his or her intake of animal-saturated fat, which goes along with a high protein intake, Getty says.

In addition, a person who avoids foods that are good sources of unrefined carbohydrates often experiences digestive disorders such as constipation and hemorrhoids, as well as weak, out-of-shape intestinal muscles. The weak intestinal muscles can lead to diverticulosis -- an infection of the colon.

Getty says too much protein can lead to a multitude of other problems. Protein acidifies the blood and discourages calcium from being deposited, leading to porous bones as well as kidney stones.

"High levels of protein causes cause calcium to be lost in the urine," Getty says. "Most Americans are already calcium deficient, and this only exacerbates the problem."

The high protein levels of this diet also put a tremendous strain on the liver and kidneys. These organs are responsible for getting rid of ammonia and urea, byproducts of amino acid breakdown.

But if none of these things are enough to discourage low-carb dieters, problems that are not life threatening, but are nuisances, may be, Getty adds.

"Bad breath and constipation go hand-in-hand with a low-carb, high-protein diet," she says.

Instead of eliminating carbohydrates if you want to lose weight, and possibly compromising your health, Getty suggests eating a balanced diet that includes plenty of fruits and vegetables, drinking eight glasses of water a day and engaging in plenty of exercise.

"This is the only proven method for long-term weight loss," she says.

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