i'm awful with kilos. but 10 kilos is about 22 lbs. .5 kilos is about 1.1 lbs. for people with so little to lose, you're not even necessarily looking at a full pound a week, .25-.5 pounds a week. yep, pounds. so that's like .11-.22 kilos a week for loss. almost a kilo, even half a kilo may be too aggressive for where you are.
the other thing is that once you reach a certain point, shape and fitness and the number on the scale aren't necessarily the same thing. the first thing you might need to do is to get your bodyfat percentage tested to see if you really have any weight to lose. if you're close to where you want to be, you may need to focus on maintaining your weight while strength training and toning so that you get the shape you're aiming for.
if you were maintaining or just slightly, slowly gaining at 2500 cals, you should be eating over 2000 cals a day to lose. take the total number of pounds you gained and multiply it by 3500. then divide by the number of days [or months or weeks] it took you to gain it. that's how far off you were a day [month, week]. for a lot of creeping weight people that number is under 200 cals. so if you were only eating 200 cals more than you needed to at 2500, that means you're maintaining at about 2300 cals a day. so eating just over 2000 cals will still give you an almost 300 cal deficit, which is in the .5 lb or .22 kilo range for loss per week.
if you were also doing that at 2500 you're above average. in other words, the numbers used to calculate are averages. so while there is you at 2300 cals a day, you're balancing out the person at 900 cals a day to get the 1200 cal a day average for someone your size . go by actual results but you may actually find yourself more sustainable at just above what the program spits out.
-google first. ask questions later.