If you want to loose wt now and you are currently cosuming 1300 cal diet, then you need to increase your daily activity or lower calorie amount. If you do both you'll loose more. To maintain wt is the hard part. In order to do that you have to eat calories less than or keep daily activity as is.. If you slack you gain it back.
1 lb of fat is equal to 3500 calories. Depending on your lifestyle and body type depends on the length of time it would take. I naturally burn 2000 calories a day with a sedentary lifestyle (inactive lifestyle) meaning that it would take me 5 days to lose 1 lb without trying. The more active you are the more calories you burn plus the body's natural burn amount subtracted from the calories you eat will equal a number that you divide by 3500 to calculate how long it would take to lose o1 lb. Also if you like eating food and want to lose weight don't go below 900 calories because your body will enter what is referred to as "starvation mode" where it stores fat instead of burning it. Bulimics only get away with eating massive amounts of calories rich foods because they rid themselves of almost all the calories they consumed through purging which is not a recommended way to live trust me.