In keeping with this philosophy, Joe starts every morning with three apples...but he only eats the peels. "Most of the fiber is in the peel, but more importantly, most of the nutrients are in the peel," he says.

Then, he tops the peels with wild blueberries, raspberries and 2 ounces of walnuts.

"It's important to eat some nuts with breakfast so that you do take in some fat, some healthy fats," he says. "I think it helps the absorption of the nutrients, and it's very filling."

Watch as Joe takes you through a day in his life. 

For lunch, Joe usually eats a large salad, loaded with vegetables. At dinnertime, he and his family enjoy lean meat or fish and more veggies.

When Joe started practicing calorie restriction, he weighed 175 pounds. Since then, he's lost 45 pounds, and he says he hasn't had a cold in seven years. Though he's in his "golden years," researchers studying Joe say he has the body of a 20-year-old athlete. "I saw my blood pressure go down substantially. My heart rate went down substantially," he says. "I had more energy than I'd ever had."