Get a small unfill then? Why would they make you super tight, and if you know you're too tight why haven't you gone in for an unfill? Either way caloric levels will vary per person. I started off eating 600-800 with minimal exercise along with a low carb diet. Now that I am exercising an hour minimum a day, I've been eating 1300 calories a day.
If you want a rough range of what you should be eating calorie wise each day, this website may be helpful http://www.healthyweightforum.org/eng/calculators/calories-required/.
If you want to do it on your own, figure out your BMR, multiply it by your activity level, and then subtract 500 from that total.
For example, my BMR is 1440 or so; that's how many calories I'd burn laying in bed. For my activity level I say I do "moderate" activity, which is usually calculated at 1.3 or so. 1440 x 1.3 = 1872. TO maintain I'd want to eat around 1800 calories. To lose, I create a deficit, so 1872-500 = 1372 calories a day. Of course this isn't perfect though it may help give you a range to play around in.
I did lose plenty eating 600 calories but it is not attainable nor healthy.