If I am going "out" to lunch, a favourite is often a large Salad - Chicken and/or Bacon & Avocado variations are normally on most menu's I find. Otherwise its a burger/steakhouse joint - I get them to do me a 6oz burger usually topped with bacon and cheese and ask for a large salad to go with it - instead of the fries and bun.

Occasionally I also enjoy Mussells - and again get them to serve me a green salad with it - instead of the usual fries :-)

Hope that helps a little.