What is the healthy weight for a 18 year old female who is 5 foot 4? i am 143 and want to lower my weight to become more healthy.

125lb: At 5'4'' you are at the average height for a woman your age.The average expected weight is 125lb. You can follow your progress using a growth chart from the cdc that features representative weights/heights for the normal population.See:www.Cdc.Gov/growthcharts.

Healthy weight: The definition of healthy weight is changing from a bmi ( 20 to 25)-- ( yours is 24.5); to overall physical and mental well being of the individual. I believe, if you have to, 10 ibs of weigh loss should be sufficient for your height.