How can you lose eight kilos in four months if you weigh 44 kg and want to weigh 36 kg?

Are you asking 0.8 kilo, 8 kilo or 80 kilo?

1) To lose 0.8 kilo, just give up junk food and exercise a little more (always a good idea).

2) To lose 8 kilo, you might want to allow around 2 months. Avoid losing weight too quickly. See the attached Related Link for an essay I wrote on how to lose a kilo or so per week in a healthy manner.

3) If you meant 80 kilo, I think it's a very risky idea. Too drastic. It would require complete starvation and would do damage. To lose 80 kilo, allow well over a year, probably more. See the Related Link.