Monday, July 21, 2008

Low-Carbohydrate Diet Best for Weight and Cholesterol

The Atkins diet may have proved itself after all: A Mediterranean-style regimen and a low-carbohydrate diet helped people lose more weight than a traditional low-fat diet in one of the largest and longest studies to compare the dueling weight-loss techniques. Moreover, the low-carbohydrate diet improved cholesterol more than the other two, although, some critics had predicted the opposite. However, all three approaches: the low-fat diet, low-carbohydrate diet and a so-called Mediterranean diet have achieved weight loss and improved cholesterol.

The study is remarkable because of the huge proportion of people who stuck with the diets (85 percent). However, it lasted two years, much longer than most.

Iris Shai, the lead author of Ben-Gurion University of the Negev, said that researchers approached the Atkins Foundation with the idea for the study. However, the foundation played no role in the study's design or reporting of the results. Other experts said the study that being published in the New England Journal of Medicine was highly credible.

The research was done in a controlled environment. It was done in an isolated nuclear research facility in Israel. The 322 participants got their main meal of the day, lunch, at a central cafeteria. Moreover, Dr. Meir Stampfer, the study's senior author and a professor of epidemiology and nutrition at the Harvard School of Public Health, said that the workers could not easily just go out to lunch at a nearby McDonald's or Subway.

Stampfer said that in the cafeteria, the appropriate foods for each diet were identified with colored dots, using blue for low-carbohydrate diet, red for low-fat diet and green for Mediterranean diet. Moreover, he said that as for breakfast and dinner, the dieters were counseled on how to stick to their eating plans and were asked to fill out questionnaires on what they ate.

The low-fat diet was no more than 30 percent of calories from fat; it restricted calories and cholesterol and focused on low-fat grains, fruits and vegetables as options. The Mediterranean diet had similar fat, calorie and cholesterol restrictions, emphasizing poultry, olive oil, fish and nuts. On the other hand, the low-carbohydrate diet set limits for carbohydrates, but none for fat or calories. It urged dieters to choose vegetarian sources of protein and fat.

Madelyn Fernstrom, a University of Pittsburgh Medical Center weight management expert who reviewed the study but was not involved in it, said most of the participants were men; all men and women in the study got roughly equal amounts of exercise.

Average weight loss for those on the low-fat regimen dropped 6.5 pounds after two years. Those in the Mediterranean diet lost 10 pounds, and those in the low-carbohydrate group was 10.3 pounds. More surprising were the measures of cholesterol. Critics have long acknowledged that an Atkins-style diet could help people lose weight. However, they feared that over the long term, an Atkins-style diet might drive up cholesterol because it allows more fat.

The low-carbohydrate approach seemed to trigger the most significant improvement in several cholesterol measures, including the ratio of total cholesterol to HDL, the "good" cholesterol. For example, someone with total cholesterol of 200 and an HDL of 50 would have a ratio of 4 to 1. The optimum ratio is 3.5 to 1, according to the American Heart Association. Moreover, doctors see that ratio as a sign of a patient's risk for hardening of the arteries.

The ratio declined by 20 percent in people on the low-carbohydrate diet, compared to 16 percent in those on the Mediterranean and 12 percent in low-fat dieters. However, the study is not the first to offer a favorable comparison of an Atkins-like diet. Research published in the Journal of the American Medical Association last year found overweight women on the Atkins plan had slightly better cholesterol readings and blood pressure than those on the low-fat Ornish diet, the low-carbohydrate Zone diet and a low-fat diet that followed U.S. government guidelines.

The heart association has long recommended low-fat diets to reduce heart risks. However, some of its leaders have noted the Mediterranean diet has also proven effective and safe. According to Dr. Robert Eckel, the association's past president who is a professor of medicine at the University of Colorado-Denver, the heart association recommends a low-fat diet even more restrictive than the one in the study. Moreover, he said that the heart association does not recommend the Atkins diet, but a low-carbohydrate approach is consistent with heart association guidelines so long as there are limitations on the kinds of saturated fats often consumed by people on the Atkins diet.

The new study's results favored the Atkins-like approach less when subgroups such as women and diabetics were examined. Among the 45 women, those on the Mediterranean diet lost the most weight. Among the 36 diabetics, only those on the Mediterranean diet lowered blood sugar levels. According to Dr. William Dietz of the Centers for Disease Control and Prevention, heads CDC's nutrition unit, these data suggest that men may be much more responsive to a diet in which there are clear limits on what foods can be consumed, such as an Atkins-like diet. Moreover, he said it suggested that because women have had more experience dieting or losing weight, they were more capable of implementing a more complicated diet.

Read also my other useful resource at Obesity Levels among Adults in China Rising Fast

Thank you for visiting SurayBlog

No comments:

Useful Posts