You need 1,200 calories at the very least because the way the body works is that if you don’t eat enough calories your body will go into starvation mode and hold on to every calorie it gets so you won’t lose any weight. I just went to a nutritionist and she really told me that my 1,200 calorie plot was still to low, and suggested i bring it up to 1,800…
It sounds like excellent food to eat you just need to up the calories.
But if you want to lose some weight before a dance the best way to do it is to stick to a excellent meal plot, cut out salts because you will save water from that, and drink a ton of water. Same as calories, when you body is not getting enough water it will hang on to whatever you get causing a maintenance of water weight, which is what you’ll be able to shed before the dance.
I know it sounds weird but drink as much water as you maybe can until the day before the dance.
Also, 40 mins of decently intense cardio a day. 4 pounds will be gone really quick i promise!References :