The jury is in: There’s no magic pill—and no one diet book—that will take the pounds off. The only tried-and-true formula is to reduce calories with a heart healthy diet, say experts at the National Institutes of Health who just concluded the Preventing Overweight Using Novel Dietary Strategies (POUNDS LOST) study.

"These results show that as long as you follow a heart healthy, reduced calorie diet, there is more than one nutritional approach to achieving and maintaining a healthy weight," says Elizabeth G. Nabel, MD, director of the National Heart, Lung and Blood Institute.

Women and men in the study ate one of four diets that included various proteins, carbohydrates and fats. Heart healthy meant low saturated fat and high fiber foods. The one common factor was lower calories, which ranged from 1,200 to 2,400 calories per day. Participants were also asked to do moderately intense exercise like brisk walking for at least 90 minutes per week.

The result: Regardless of the dietary formula, they all lost about the same amount of weight—13 pounds at the 6 month mark—and maintained a 9 pound loss 2 years out from the study. They also lost an average of 1 to 3 inches in their waistlines by the end of the study. Cravings, fullness, hunger and diet satisfaction were all comparable among the 4 diets.

This is good news for the 66% of Americans who are overweight (body mass index [BMI] of 25 to 29) and of those, the 32% who are obese (BMI of 30 or more), CDC experts say.

Perhaps more importantly, all of the diets improved participants’ risk for heart disease through healthier blood pressure and improved cholesterol levels, including increased HDL levels, the good cholesterol. This jived with prevailing studies showing that if you’re overweight, just losing 5% to 10% of your body weight can create dramatic health improvements.