You won't be harrassed at the airport, regardless of what you're carrying. most customs officers are polite and fair.
Generally, snack items and other groceries for personal use by visitors are okay to bring in. I'm told that recently there has been a change on the policy about bringing in meats (used to be you could bring in some for personal use as long as they were in sealed packages with government USDA stamps but that now that is more iffy.)
Don't bring in any fresh fruits or vegetables, as those could carry diseases.