If you have some doubts about your weight, you can consult the doctor
. Doctor will examine you and check your body mass index which can estimate the fat content in your body. If necessary, doctors can give you some advice to let you put on weight gradually or keep the present weigtht. For the children, if the doctor advises them to lose weight, then they should carry out losing weight under the guidance of the doctor. You can also ask the nutritionist for help. They know how to maintain necessary absorption of nutrition and to reduce calories in the meantime.