As I pointed out before, food prices are going up. While we as consumers feel the pinch a lot, restaurants do, too. A lot. The battle between price increases and portion size reductions wage on, per this article via (The Delicious Life). It also references some interesting techniques restauranteurs use to help their bottom line. For example, trimming down a cut of meat while adding more low cost sides makes people think they're getting value for money. It's all about covering that plate.
On a related note, a friend pointed out this article about Sysco's monopolization of restaurant's food distribution. From cereal to dish-washing detergent to chicken parts molded to look like chicken breasts, if you want it, Sysco's got it. What's more, they sell frozen products like cakes, which restaurants can (and do) turn around and sell to patrons at...oh, let's say $9 per serving. But hey, they do toss on some berries for good measure ;-)
It makes sense, though. Restaurants only have so many resources, so they can't make everything from scratch. Most don't make their own desserts, just like most people don't make all of their desserts at home. Can you imagine making all of your own salad dressings, sauces, and ice cream. I'll take Ben & Jerry's any day. In fact, I usually do. In fact, I've got to go do something.