Is That Extra Piece Of Cake Worth It?

Deciding whether to eat a given food is a balancing act between its nutritional value and how much it could add to your waistline.

So, you probably wonder how much exercise you'd have to do to work off the calories in various foods.

Enter "diet detective" Charles Stuart Platkin.

In his new book, "The Diet Detective's Count Down," the nutrition and public health advocate translates food into exercise, with charts that break down the number of calories, fats, and carbohydrates in more than 7,500 popular foods and drinks into the minutes of walking, running, biking, swimming, yoga, or dance needed to burn them off.

Knowing you'd have to walk 14 hours, roughly 43 miles, in order to burn one pound of fat might be reason enough to skip that dessert that's tempting you!

In part two of a three-part Early Show series on nutrition, Platkin crunched the numbers for co-anchor Julie Chen.

For instance, a typical glazed doughnut is 350 calories. Platkin says it would take an-hour-and-a-half of walking, 50 minutes of biking, and 37 minutes of running to consume that many calories.

"That's not (meant) to ruin your day," Platkin said. "We all get a daily caloric budget. If you eat the daily caloric budget, you will not gain weight and you will not lose weight. It's once we go over that daily caloric budget -- that means, the more we eat, the more we have to exercise to burn that off."

The number of calories in someone's daily caloric budget depends on his or her age, gender, and weight. Platkin pointed out that To see an excerpt of "The Diet Detective's Count Down," click here.

To read answers to more questions put to Platkin, click here.

"The Diet Detective's Count Down" is a Fireside Paperback. Fireside is part of Simon & Schuster, which in turn is part of the CBS Corporation, as is CBSNews.com.