On two different intercontinental flights Ive had food liberated by tsa checkpoints.You can take food, assuming it's not liquid. A cheeseburger or chicken sandwich is fine, done it many times and sent my SIL who loved McD's chicken sandwich off with a sack of them.
Relevant from TSA website:
Nuts
TSA officers may instruct travelers to separate items from carry-on bags such as foods, powders, and any materials that can clutter bags and obstruct clear images on the X-ray machine. Travelers are encouraged to organize their carry-on bags and keep them uncluttered to ease the screening process and keep the lines moving.
- Carry On Bags: Yes
- Checked Bags: Yes
https://www.tsa.gov/travel/security-screening/whatcanibring/food?page=0 breaks it down, but seeds aren't specifically listed so I just went with nuts as the closest.
Maybe he just wanted the turkey jerkey and gummy bears for himself?