I read this article on MSN health & fitness and Oh.My.Gawd!
So, if you get the urge to eat some fast food:

Eat This:

McDonald's Big Mac
540 calories
29 grams (g) fat

Not That:

Burger King Whopper with Cheese
760 calories
47 g fat

Save 220 calories and 18 grams of fat!

In the battle of the megaburgers, the McDonald's triplex is the surprising victor. BK's burger barons have a heavy hand with the mayo (it contributes 160 calories to a Whopper), and apparently the charbroiling isn't doing you any favors, either. But don't take this as an all-you-can-eat Big Mac pass: If you add a medium order of fries and a Coke, your lunch just grew to 1,130 calories.