Three popular diets improve health, weight loss slightly

William Atkins
Thursday, 17 July 2008 22:33

Science - Health

According to a new Israel-U.S.-Canada study on three popular diet plans, moderately obese dieters lost, on average, only six to ten pounds over a two-year period. However, they were able to reduce their cholesterol level and other important indicators of health.


The result of the study was published in the Thursday, July 17, 2008 issue of The New England Journal of Medicine.

The article, “Weight Loss with a Low-Carbohydrate, Mediterranean, or Low-Fat Diet,” was authored by Iris Shai, a researcher in nutrition and chronic diseases at Ben-Gurion University of the Negev, Beer-Sheva, Israel.

Her research team consisted of Dan Schwarzfuchs, Yaakov Henkin, Danit R. Shahar, Shula Witkow, Ilana Greenberg, Rachel Golan, Drora Fraser, Arkady Bolotin, Hilel Vardi, Osnat Tangi-Rozental, Rachel Zuk-Ramot, Benjamin Sarusi, Dov Brickner, Ziva Schwartz, Einat Sheiner, Rachel Marko, Esther Katorza, Joachim Thiery, Georg Martin Fiedler, Matthias BlüherMichael Stumvoll, and Meir J. Stampfer

They are associated with Harvard School of Public Health (U.S.), Robarts Research Institute (Canada), Soroka University Medical Center (U.S.), Brigham and Women's Hospital (U.S.), Harvard University (U.S.), The Nuclear Research Center (Israel), Ben-Gurion University of the Negev (Israel).

The study was conducted as part of the Dietary Intervention Randomized Controlled Trial (DIRECT) Group
 
The initial intent of the study was to compare “the effectiveness and safety of weight-loss diets” by using longer “follow-up times” (than what was normally used in previous trials) and minimizing “high dropout rates” (which was also frequently encountered in previous trials).

The researchers used 277 male dieters and 45 women dieters; in all, 322 moderately obese persons. The average age of the dieters was 52 years at the beginning of the study, and they had an average body mass index (BMI) of 31.

A BMI is a measure of body fat based on an adult’s height and weight. A person with a BMI under 18.5 is considered “underweight”; while 18.5 to 24.9 is considered “normal weight”; 25 to 29.9 “overweight”; and over 30 is “obese.”

The researchers weighed each subject on a monthly basis. Other measurements such as cholesterol and blood sugar levels were taken four times during the two-year study.

Each dieter was assigned one of three popular diet plans: either the (1) low-fat diet based on guidelines from the American Heart Association, which restricts fat to about 30% of the entire diet; (2) Mediterranean diet, which is based on the studies of Harvard Medical School researcher Walter Willet; and (3) low-carbohydrate diet based on the Atkins Diet (Atkins Nutritional Approach), which was formulated by Dr. Robert Atkins.

Please read page two for specifics of the three diet plans.