1 kilograms = 2.20462262 pounds
1 centimeter = 0.393700787 inches
shinobu, to convert kilograms to pounds, multiply the kg's X 2.2
In other words, if you are 49 kg, multiply that by 2.2. You would weigh 107.8 lbs (round it off to 108 lbs for easier reading).
If you want to lose 10 kg, you would be wishing to shed 22 pounds.
If you currently weigh about 108 lbs, and want to lose 22 lbs, your goal weight would be 85.8 (or 86) lbs.
If your height is 147 cm, you are 57.9 (round off to 60) inches tall, or 5 feet tall.
For your height, 39 kg (86 pounds) may still be underweight, or bordering underweight.
Here is a link to a URL with some ways to calculate your ideal weight: http://www.halls.md/ideal-weight/devine.htm
According to the various calculations for ideal weight, as a 20 year old woman, ideally, you should weigh about 45.5 - 49 kg at your height or within 15% (about 7 kg)
of that number . You probably don't need to lower your body weight. You may better need to develop lean muscle so that your body is healthy, lean-looking and well-proportioned. You can develop lean muscle and become trim looking by weight lifting (or other resistance exercises). As a woman, you would not need to lift very heavy weights. You can look much more slender and feminine, but it's infinitely more healthy than trying to be underweight. You could do 15-20 repetitions of each exercise with medium weight free-weights and/or with resistance machines at a gym. You can also do resistance exercises without equipment, such as pushups, pullups, squats, lunges, sit-ups, etc. A trainer at a gym could help you if you don't know how. If you don't have access to a gym or weights, you can search online for "resistance exercises." You'd need to do the exercises only about 3 times a week for about 20-45 minutes. Doing these exercises, you might even turn into a ninja-in-the-making!
You noted on your SLD profile that you live in Indonesia. If you are an Asian young woman, it sounds as if you are probably already slender, perhaps small-boned, but may wish to be more slim? Your avatar name indicates you must really enjoy anime and manga :^D... our eldest grandson (soon to be 14 yrs old) gave himself an avatar name of Takashi, and busied himself over the summer by learning to make personal blog/websites using his favorite anime images. For his birthday, he and I are going through jbox.com, eBay and other online sources, looking at anime costumes, tattoo-sleeves and other items of anime/manga interest -- one thing of whatever he chooses (within reasonable budget) will be his present. Fun.
back-to-school day comes—
flying through a dream into