You can eat only 1000 calories a day, but it's not healthy if you do it for more than a week. A good way to figure out how many calories you body needs is to take your weight, multiply by 10, then add your weight. (325*10=3,250+325=3,575) So I would recommend keeping track of everything you eat, see how many calories you normally consume, and go from there. I also suggest that you start exercising. I run in my room every other night for 10 minutes in place and it really helps me jump start my metabolism. I lost about 30 pounds by eating about 1500 calories a day for 4 months ( I was 175, and I'm 148 now and I'm 5'1"), I hope this helps you too.