"Starvation mode" is a real thing, but it isn't caused by eating a certain number of calories, and it doesn't mean what people think it does. Check out this thread for details (scroll down to Coach Dean's response. I'm campaigning to have that post turned into an article!) www.sparkpeople.com/myspark/messageboard.a
Remember that your body is not a calculator. Even if all the numbers "add up", that doesn't always translate to the scale. That's because your scale numbers are affected by more than calories in/calories out!
Know that your body IS changing, even if the scale isn't cooperating. Adding exercise can also temporarily mask the scale's changes by causing temporary water retention in your muscles.