I have merged this thread with the one called "nutritional information" because they are the same issue.
Here is the response from the tech side of the site:
Daily Value is the standard that's used on food labels. It is not keyed to age/gender. It is the same for everyone because you can't customize a food label per-person. %RDA is published by the government for specific age/gender groups.
FitDay's uses these numbers to customize %RDA for each individual. The numbers are perhaps more accurate than our users are expecting.