All Diets Work if you Count Your Calories and Eat Less

Calorie counts were assigned individually to each dieter based on subtracting 750 calories from their daily caloric needs. Participants were asked to attend group sessions and use self-monitoring tools, such as diaries. They were also asked to exercise moderately for 90 minutes a week.

At the six-month mark, participants assigned to each diet had lost an average of 13 pounds (six kilograms). Among the 80 per cent who completed the program, the average weight loss was nine pounds (four kilograms) at two years. Waistlines were reduced by an average of two inches at the end of the two-year period.

"There really wasn't magic revealed in the specific composition of the diet," said Dr. Howard Eisenson, executive director of the Duke Diet and Fitness Center. "I thought their conclusions made sense and jibed with what many of us in the field have long been thinking."

In addition to weight loss, subjects reduced their risk of heart disease and diabetes and improved their blood pressure.

"The biggest influence is in the individual response, not the diet type," he says. "That's something we ought to delve into and understand better."

In an editorial appearing in the same issue of the journal, diet researcher Martijn Katan, from the Institute of Health Sciences at VU University, Amsterdam, suggests that Dr. Sacks's findings illustrate the need for a societal, rather than individual, approach to combatting growing obesity rates.