Answer:
The pressure exerted by the sharp knife edge is more than that exerted by the blunt one because the area on which force is exerted with a sharp knife is very small.So blunt knife cannot cut the vegetables properly.
Mental and emotional you need to be a genuine good person
Your audience should probably be adults. If adults learn the healthy habits of eating they can pass it on to their children and friends. Maybe posters or news segments could work to spread the news. This idea could work because adults watching the news segment and Billboards will choose not to pick up that snickers in the grocery store check out but instead trail mix.
Thats all you will need, just elaborate a bit more!