[Evermind]

Just fyi -

You are either in ketosis, or you aren't. There aren't degrees of ketosis. The difference in color on a ketostix is just due to concentration of urine -if you are drinking enough water, it will just show pink, whereas if you haven't had a lot of fluids, it'll be purple. Either way, you're in ketosis. And that's it. (most of us don't use the stix.)

If you only ate 400 calories, we have a problem, Houston. Get an account at Fitday.com. Answer all of the site's questions about height, weight, and activity level. If you click on the "Activities" icon, it will show you a table that tells you how many calories you are burning per day. The second line on that table says "basal". That number is the amount of calories you should be eating every day, give or take a hundred or so (up or down). If you go much below that, you will enter starvation mode and stop losing, because your body will be striving to keep you from what it perceives as possible imminent death.

So eat! Eat, I tell you! And stop worrying about the ketostix!