|High-carb diets may be better than low-carb diets|
In contrast with popular reports that low-carbohydrate diets are safe and effective for weight loss, a study by researchers at the U.S. Department of Agriculture found that people consuming a high-carbohydrate diet are more likely to have low body mass index (BMI) values.
More than 10,000 U.S. adults were asked to recall in detail all that they have eaten in the last 24-hour period. The researchers looked at carbohydrate intake, nutritional quality, and BMI. The group was divided into four groups: very low carbohydrate (30% or less of total energy intake), low carbohydrate (31 - 45%), moderate carbohydrate (46 - 55%), and high carbohydrate (more than 55%).
Results showed that while those in the high-carbohydrate group ate the same amount of food (calculated by weight) as those in the other groups, they actually consumed 200 - 300 fewer kilocalories and less fat. Women in the high-carbohydrate group had significantly lower BMIs than those in the lower carbohydrate groups. Men on the high-carbohydrate diet also showed a tendency toward a lower BMI, but this was not statistically significant. There was also greater intake of vitamin A, carotene, vitamin C, folate, calcium, magnesium, and iron among the high-carbohydrate group, and a lower amount of vitamin B12, zinc, and sodium.
The study authors concluded that "adults who obtained more than 55% of total dietary energy from carbohydrates had [a lower calorie], yet nutritious diet." High carbohydrate diets tend to include foods high in fiber and water content and low in fat, such as grains, fruits, vegetables, and reduced-fat dairy products. In contrast, authors warn that the low-carbohydrate diets popular among the public may not be low enough in calories and may be devoid of essential micronutrients.
Exactly what type of diet is best for losing weight is still unclear, however. Other studies suggest that many kinds of diets can help you lose weight -- as long as you stick to the diet. Most dieters know how hard this is. But take heart: Studies have also shown that some people do keep dieting when they see positive weight-loss results and know that they may be reducing their risk for heart disease.
Bowman SA, Spence JT. A comparison of low-carbohydrate vs. high-carbohydrate diets: Energy restriction, nutrient quality, and correlation to body mass index. J Am Coll Nutr. 2002;21(3):268-274.
Dansinger ML, Gleason JA, Griffith JL, et al. Comparison of the Atkins, Ornish, Weight Watchers, and Zone Diets for Weight Loss and Heart Disease Risk Reduction. JAMA. 2005;293(1):43-53.
Reviewed By: Jeffrey Heit, MD, Internist with special emphasis on preventive health, fitness and nutrition, Philadelphia VA Medical Center, Philadelphia, PA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.