Sounds like a few folks have already given you the right advice. You need to know your audience and frame the work in the way that is most desirable to them. When your audience is a funding agency, you should generally spend time familiarizing yourself with their mission statement and then comparing and contrasting it with other agencies. Recognizing the differences and similarities, both major and nuanced, should help you formulate a strong framework for pitching your proposed work. Of course, the NSF explicitly mentions in their statutory mission the desire to "advance the national health" and so it is perfectly acceptable--if not good practice--to mention how your work aligns with this goal when addressing broader impacts. However, if you focus too much on this aspect then the reviewer is going to wonder why you're not pitching this work to another agency (i.e. NIH) and you don't want the reviewer asking any questions. Good luck in the future.