(CBS)  Looking to live a long, healthy life? As CBS News correspondent Mika Brzezinski reports, for people like Joseph Cordell, that means counting every single calorie (video).

Forty-seven year-old Joseph Cordell is not only counting his calories, but counting on every single one.

"This is all about getting the most bang for your buck nutritionally, trying to squeeze the most nutrition out of the fewest calories," Cordell says.

In Cordell's case, that means he eats about 30 percent fewer calories than most people.

"Green peppers," he remarks. "Wonderful."

And he restricts his choices to food with the very highest nutritional value. It's called "calorie restriction optimal nutrition," or C.R. for short.

"The whole idea of calorie restriction is recognizing that calories are basically bad for you," Cordell says.

So, what does he eat? Well, twice a day, he eats a big bowl of "blueberries, nuts, and apple peels," he tells me.

That's right, just the peel. The peel is where the most nutrition is stored.

For lunch, Cordell eats a huge salad made up of the right kinds of food.

He has it down to a science. "I bet the calories on my plate, which is significantly larger than yours, are certainly no more than 300, maybe less," he says.

His largest meal is dinner with his family. Tonight, that means another salad, broccoli, asparagus and salmon.

Known as the "120 Year Diet," followers believe they'll live a lot longer by eating a lot less.

"Definitely his life expectancy is higher than an average American," Dr. Luigi Fontana says.

Doctors like Fontana are conducting long-term studies of C.R. They're convinced it protects against major diseases.

Dr. John Holloszy, principal investigator, agrees. "There's no chance of them getting type 2 diabetes, they have very low blood pressure, and the risk of them developing cancer is markedly decreased," Dr. Holloszy says.

And exercise? Not an option. C.R. dieters simply don't have the calories for it.

"The calorie restriction protects them from the same diseases that exercise protects against, and more potently actually than exercise," Dr. Holloszy says.

His doctors say Cordell's has the blood pressure of a child, the cholesterol of a teenager, and his risk of heart disease is close to zero. Average middle-aged men have 23 to 25 percent body fat; Cordell's is 7 percent.

"If there wasn't a substantial benefit to C.R., no one would do it," he says.

For Cordell, the potential payoff is worth eating this way, something many of us might have a hard time with.

Cordell understands. "Americans, many Americans, are not good at deferred gratification," he says.

What are Americans good at?

"Gratification," Cordell says.

It's not about a short term new year's resolution; it's about a complete diet overhaul that Cordell will stay on for what he believes will be a longer, healthier life.

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