Bad Cholesterol How To Stop Im 19yrs Old, Im Thin And My Weight Is 45 And My Hieght 160cm And My Cholesterol Is 227,is It Really Bad?

Im 19yrs old, im thin and my weight is 45 and my hieght 160cm and my cholesterol is 227,is it really bad? - bad cholesterol how to stop

The pharmacist told me that I am underweight and I have to stop eating, fatty foods, but the weight at the same time, how is this possible? I wonder what could be causing this? Moreover, my father was a heart patient, why?