Life Without Carbohydrates?

Sharon Howard, R.D.
drkoop.com Health Columnist

“Carrots are bad for you.”

“Bananas have too much sugar.”

“Bacon and eggs are the best way to start the day.”

Thus goes the nutritional misinformation backlash from the popular low-carbohydrate dieting trends. What starts out being a low-calorie diet plan that appeals to the meat-and-fat lovers becomes a litany of false messages sent to the public about what a healthy diet is and what foods are good for us.

Why Are Low-Carbohydrate Diets Popular?
Because we Americans just don’t know moderation and portion control. Weight control is still clearly based on the fact that you need to exercise more and consume fewer calories to lose weight. Diet plans that let us eat all we want of certain foods are very appealing.

In the ’90s, calorie counting went out as we shifted our dieting focus to fats. After all, fats are more than double the calories of proteins and carbohydrates, so when you take the hidden fats out of the diet (as well as the obvious ones in fried foods, gooey desserts and ice cream) you reduce your calorie intake and lose weight. You even have glucose available to exercise.

That worked until the arrival of the “fat-free fun foods.” Lower-fat diets were helping many people clean up their eating and lose weight. But the lure of a box of fat-free cookies could not compete with a low-fat apple. “Fat-free” somehow mistakenly got translated into “Eat all you want -- it has no fat!” So, as Americans gorged on fat-free frozen yogurt, bagels, cookies, potato chips and pretzels, their weight went up again. What failed was the dieter’s understanding of what really matters in weight loss.

Then along comes the revival of the low-carbohydrate, high-protein, high-fat diets. (“Wow, all the steak I can eat! I love the taste of butter and oil, and I missed it so much!”) As a bonus, the dieter quickly drops some water weight in the beginning. Starchy foods hold onto water and when they are removed from the diet, a diuretic effect occurs. So, the falling numbers on the scale inspire the dieter.

As the body is depleted of glucose, it adapts to this abnormal diet by developing ketosis, which causes fat and protein depletion, kidney stress, anorexia, diuresis and bad breath. As glucose and glycogen stores are depleted, the muscles lose their main energy source. The dieter is more fatigued, cannot sustain aerobic exercise to maintain cardiac health and cannot perform enough strength training to protect the body from muscle loss.

But why do the low-carbohydrate dieters, who start out successful, get stuck at a certain weight and then start gaining it back? If muscle has been sacrificed during weight loss, the body’s metabolism (the amount of calories your body needs to stay alive) decreases. At some point, calorie intake meets the lower body-weight needs and weight loss stops. More often, people start coveting foods such as baked potatoes, watermelon or corn on the cob. When they add these foods back into their diets, the ketosis stops, they regain their normal appetites, but keep eating the high-fat, high-protein foods -- and their weight goes back up.

Why Are Carbohydrates Good for Us?
Contrary to popular opinion, carbohydrates are necessary to our health because these foods provide energy, vitamins, minerals, antioxidants and other phytochemicals. It’s the types of carbohydrates that are overused -- sweet drinks, desserts, candy, larger portions of bread, pasta and refined starches -- that get us into calorie trouble. Fruits, vegetables, whole grains and dairy products are high-carbohydrate foods that are essential to our good health. Whole grains such as breads and cereals are high in fiber. Fiber helps lower blood cholesterol. Fiber helps us feel full longer so we don’t crave junk foods between meals. Fruits and vegetables, also carbohydrate sources, contain fiber and phytochemicals, which may help fight off heart disease and cancer.

What is a high-carbohydrate diet? Carbohydrates can easily make up 45 percent to 60 percent of a balanced, healthy, weight-reducing diet. For example, if carbohydrates make up 50 percent of a 1,500-calorie diet, that is equivalent to 187 grams. In healthy food terms, this amounts to two servings of milk or sugar-free yogurt, four servings of fruit, four servings of vegetables and five servings of whole-grain starches. A high-carbohydrate diet can also consist of soda, candy, cookies, 12-inch hoagie rolls, a pound of pasta at a restaurant, and a half bag of pretzels at your desk. These are the carbohydrates you want to reduce to lose weight -- not the brown rice with your chicken or the whole-wheat bread with your tuna salad

With low-carbohydrate diets you risk losing B vitamins, calcium and potassium. In addition, there is loss of possible protection from cancer and heart disease. The good news about the low-carbohydrate diet is that you consume fewer sugars and junk foods, which really contribute many empty calories to the diet. Limiting these foods, but eating moderate amounts of whole grains, fruits and dairy foods would be a healthy compromise.