Cracking the Low-Carb Code
Low-carb dieting is popular with people seeking speedy weight loss without counting calories. Find out whether going low-carb is a good strategy for you.
By Madeline Vann, MPH
Medically reviewed by Pat F. Bass III, MD, MPH
For a while, low-carb diets like Atkins, the Zone, and South Beach were all the rage, causing people to toss pastries and pasta in favor of protein. Yet success in these diets, as with any weight-loss program, is linked to simply eating less — you may not really be immune to counting calories, no matter what program you’re on.
Low-Carb: An Alternative to Counting Calories?
National nutritional recommendations are for adults to get 50 to 60 percent of their calories from carbohydrates. Bread, pasta, cereals, and rice are among the kinds of foods that are high in carbohydrates, but fruits and vegetables also contain carbs.
Low-carb diets call for you to cut back on foods that contain carbs, but to varying degrees: Atkins recommends that less than 10 percent of your calories come from carbs, while the South Beach Diet is slightly more flexible, but strongly emphasizes “good” carbs (those low on the glycemic index) over “bad” carbs (refined white sugars, flours, and the like).
Low-carb diets may have become so popular because they speed weight loss in the first six months and because counting calories can be complicated, says Naomi Reyes, RD, a dietitian at the Temple University Center for Obesity Research in Philadelphia.
“Your weight is directly related to the number of calories you consume, but trying to avoid certain food groups is a little more straightforward,” says Reyes. People on low-carb diets often cut back on their calorie load by avoiding all refined grain products, for example.
One of the questions about low-carb diets is whether dieters can keep offthe weight. A study of 55 dieters who had already lost weight looked at whether a low-carb diet or a low-fat diet worked best to maintain their weight loss. The results were about even: Half in each group regained weight and half continued to lose weight. Among the low-carb dieters, those who ate the most protein were the ones most likely to continue to lose weight.
Low-Carb: The Controversy Over Safety
Low-carb diets have been controversial because of the possible short- and long-term health implications of cutting out whole food groups and heavily emphasizing protein and saturated fat
as calorie sources. Indeed, a small research study showed that the high-fat Atkins diet can increase “bad” LDL cholesterol and reduce blood vessel function. Another study published in the journal Appetite indicates that no-carb or low-carb diets can have adverse affects on memory function.
In contrast, other studies have shown low-carb diets to be beneficial for people with metabolic syndrome (a predisposition to diabetes and cardiovascular disease, among other illnesses) or diabetes because these diets decrease fasting glucose and insulin.
Low-Carb: The Dieting Risks for Women
Women should protect their bone health while on a low-carb diet, warns Reyes. “Any type of restrictive diet is potentially damaging to your bone health,” she says. “Take a calcium supplement and do weight-bearing activities to strengthen your bones.”
Reyes adds that there is one group that should definitely avoid a low-carb diet: women who are pregnant or hoping to become pregnant. Carbohydrates are necessary for the health of your baby, Reyes explains.
Low-Carb: Is It Right for You?
A recent study of 322 dieters published in the New England Journal of Medicine found that a low-carb diet was just as effective as a low-fat or Mediterranean-style diet in promoting weight loss over two years.
One possible reason is that losing and managing weight it is not about the type of diet you choose, explains Reyes. It's about choosing a healthy lifestyle.