GDA - Guideline Daily Amount

heyy everyone!! jst one ques... about GDA (or RDA)

nowadays most products hav the nutrient info on the boxes with the percentage of GDA of the nutrients it contains.. ie 20% fat... etc..

bt are these recommended daily amounts necessary to stick to?? dnt they vary frm person to person.. according to their metabolic rates... n also according to how active they are??

kansha x