It sounds like a trick question, I know. Is a calorie a calorie? For many years, the conventional wisdom has been yes, that a calorie is simply the energy derived from eating a particular food. An apple might have, say, 80 calories, and a cookie might have 200 calories. Eat three apples and you have the rough equivalent of the cookie.

But lately, scientists and nutritionists have come to a different point of view. That is, not all calories are created equal, and fruit and vegetables, which are high in fiber, are not digested the same way as processed food. As Mark Bittman notes in his piece in the New York Times, “Fiber is special because it’s not digested or digested incompletely. Most of its calories don’t get into the body, which is one reason why fruits and vegetables, which are high in fiber, help with weight loss.” It’s also the reason why people who adhere to a raw food diet remain thin even when they eat the same number of calories as those who eat cooked and processed food.

Bittman’s piece is really a commentary on Why Calories Count, a new book by Marion Nestle and Malden Nesheim, and it’s one I plan on reading sometime soon. Nestle told Bittman “There are dozens of factors involved in weight regulation. It’s hard to lose weight, because the body is set up to defend fat, so you don’t starve to death; the body doesn’t work as well to tell people to stop eating as when to tell them when to start.” (The emphasis is Nestle’s.)

Nestle also said, “If you’re eating a lot of fruits and vegetables, you’re not taking in as many calories as you would if you were eating fast food and sodas.”

Weight Watchers has recently adopted this point of view—albeit with a fair amount of controversy—and in its point system, fruit now has zero points.

In my own Controlled Cheating diet, where I diet for 6 days and “rest” on the 7th, I eat lots of fruit and vegetables on my noncheating days. I figure I easily reach the recommend “5 a day.” And, lucky me, even though I love sweet, sugary food, I also love fruit and vegetables, which means eating them is a pleasure rather than a chore.

So far, I’ve lost nearly 50 pounds. Onward with the fruit and vegetables!