CHICAGO (CBS) — Two guys have come up with what they believe is the perfect diet to get Americans off the obesity track.

They call it the Lifesize diet, and it doesn’t involve counting calories.

“It’s really just about portions. That’s it, it’s just one thing – it couldn’t be more simple,” says Steven Kates.

He’s a trainer who says forget calories, just control the size of your food.

That’s how he helped his business partner, Myles Berkowitz, lose 50 pounds. Now the two have come up with a portion control system with measuring devices for what you eat.

For a typical meal, you cut your meat to fit into the meat container, then measure your carbs in the carb cup. Fill the rest of your plate with as many fruits and vegetables as you want.

They claim no food is off limits — pizza, ribs or ice cream – as long you measure it and follow the portion sizes.

“For losing weight, it’s all about the food,” Kates says.

The Lifesize kits are selling for around $80 and supposedly work equally well for both men and women.

Nutritionists say measuring is not a bad idea because we tend to eat portions that are too large.