One week lose about 20 lb?

Yes, I did! I am 6'5'' asian girl.

Last year, I suffered a lot of stress, and I gained 10 more ponds cuz I ate a lot nuts and cheese, then the following semaster, I suffer more more stress and study more, stayed up for studying, then I lose about 20 more ponds in one week. I lost it in short period so I am not so healthy and lost some hair. Damn! I used to have long and black hair which looked very natral and beautiful, but now my hair is not black but brown (BTW, I did not dye it -_-!)

I wanna become healthy and look health either. How can I do? Yoga? or sth?

One week lose about 20 lb?

Yes you can do yoga and exercise regularly... eat healthier foods like salads, fruits, less fried stuff, and instead of eating three BIG meals a day.. eat 6 smaller ones. just make sure you get all the basics in.