Let's do some math...with some assumptions!
Please keep in mind that I am not promoting eating below the amount of calories that is SAFE for
YOUR body! For men, that is
typically not below 1,600 and for women 1,200.
Loss desired: 10kg = 22lb
Time: 14 days
Gender: Male (?)
Weight: 171lbs
Height: 5'7" (?)
Age: 25 (?)
BMR (Total daily calories just for living): 1,750
TDEE (Total daily calories if you have an office job and do not exercise): 2,100
For the sake of answering your question, even if you ate nothing for 14 days straight, you would lose 8.4lbs in 14 days.
Now let's get crazy and say you ate nothing and also exercised for an hour and burned 500 calories.
You would lose an additional 2lbs, for a total of 10.4lbs and you win...a complete loss of your sanity and health!
A healthy and strong approach would be to cut 500 calories a day from your food which would put you at around 1,600 (if completely sedentary lifestyle) and exercise an hour a day to burn an additional 500 calories a day (30 minute walk, 10 minute run, 20 minute elliptical.) In 80 days / 2.75 months you would reach your goal. If you do not exercise you will meet your goal in 159 days / 5.3 months.
Hope this helps!