Well, there isn't any. People sometimes exclaim with shock that we "gave up meat" to do this, but we haven't eaten it at home for years. I'm a flexitarian for health, environmental, and moral reasons, eating meat only in social situations where not doing so would be rude. To me, good vegetarian meals like the ones featured here are simply more interesting and tasty. [Beginning in December 2011, new recipes also skip milk, cheese, and eggs for several reasons.]
But that doesn't mean that you can't add some meat. Especially when you first get started, you might want to roast a chicken once a week, then have chicken and rice one night, and then finally make chicken soup with the bones. Have a tuna sandwich or put some pepperoni on a pizza. Use meat sparingly as a garnish or as a treat for a special occasion, such roasting a turkey at Thanksgiving. Even if you just switch one meal a week from meat to beans, you will be saving money and doing good. If you can, use the money you saved to buy meat that has been humanely raised and not loaded with hormones or antibiotics.