It’s very individual, what you weigh. Some people are naturally slim, others are slightly heavier built. Women develop a higher percentage of body fat during puberty – it’s a prerequisite for having periods. If you exercise regularly (at least half an hour a day is good!) and eat proper meals, rather than snacking all the time, your weight is probably appropriate for your body. BMI (body mass index) can give you an indication of what you should weigh. It’s a simple mathematical calculation that acts as a reference figure. If you’re uncertain as to whether you weigh what you should, talk to your school nurse or a young person’s clinic.