From the Slap-Your-Forehead and Shout, "Duh!" Files

Common sense, really.

In the long run, it's the calories - not the fat, nor protein, nor carbs - that matter, according to a new study comparing diets.

Weight-conscious Americans snap up the latest diets, from the low-fat Dean Ornish approach, to the high-protein Atkins plan, to the compromise called South Beach. But scientific studies evaluating the diets' effectiveness have had mixed results, frustrating consumers who struggle to shed pounds.

A team led by Dr. Frank M. Sacks of the Harvard School of Public Health designed a clinical trial that randomly assigned 811 men and women to spend two years on one of four reduced-calorie, heart-healthy diets with different levels of fat, protein, and carbohydrates. The dieters were asked to exercise for a total of 90 minutes each week and were invited to attend regular group sessions, in addition to receiving periodic individual counseling.

"What we found is that the most important thing for people to lose weight is to choose a heart-healthy diet and to keep the amounts down," Sacks, lead author of the article appearing in the New England Journal of Medicine, said in an interview.

"It's not so important whether they eat higher carbohydrates or higher protein or lower carbohydrates or lower protein," he said. "What really matters is just plain, simple old quantity: how much people eat."

Or as Sparky once said:

I want you to think of what you ate today. Got it? Now cut that in half, this is called a diet, people, everyone start one today!