You're not eating enough. I don't know your height, but if you're working out that much you need to be eating more.
Depending on your height, you are probably already at a healthy weight. When losing "vanity lbs" you need a smaller deficit, like 300 cals per day to lose a little more fat and start lifting heavy weights to change your body composition. More muscle less fat lets you look leaner, even if you don't lose a lot of lbs. Also if you have been dieting for a long time, your body adjusts and burns less cals, especially as your intake has been low. You need to eat more for awhile to up your metabolism again.
Would pilates be an appropriate activity at all? Should I have a calorie deficit of 300 after or before exercise? It's been about 4 weeks that I have been dieting.. Is that a long time? Should I be aiming for closer to around 1400 calories?
How old are you? That makes a difference in your cal requirements as well. And by lifting weights I mean New Rules of Lifting for Women, Female Body Breakthough or Starting Strength. Free weights, dumbells, barbells, and not the pink dumbell barbie weights. Squats, lunges, dead lifts, rows, etc. Your deficit should be after considering daily activity and exercise. It has to be something that challenges your muscles and forces them to get stronger.
I'm 22. So what you're saying is that I should up my calorie intake and by the time I consider my exercise deficit, my total deficit of the day should be at around 300. Just out of curiosity, why does the calorie deficit need to be smaller when losing "vanity lbs"? (Sorry I'm new to this!)
Yes, total deficit around 300. A smaller deficit works better because when you are at a healthy weight, the body is more reluctant to let go of fat stores. Plus a smaller deficit keeps you from losing lean mass (muscle) as you lose fat. In fact you could probably eat close to maintenence and concentrate on weight lifting and lose inches, get leaner, without have to lose much in lbs at all. It will probably take a few months to really see a difference so have patience. Also make sure you are eating "clean", healthy fats, fruits, veggies, plenty of protein. Avoid processed foods and refined sugars. Cut back on grains (bread, pasta, etc)