Salad went thru fine (they kind of laugh at it).
Delicious yoghurt and strawberries made at home (P3), uh, no.
They let me exit the line, eat it as fast as I could, and gave me kind of cuts in line to go back thru. (Small airport, not a very long line)
Other people had yoghurt for their kids, but it was the sealed in a container kind (couldn't tell if they bought it at the gate or tried to check it).
Packets of all kinds go thru easily. I usually just bring the shaker empty, then fill it with water once you are at the gate to make a shake or pudding.
Some airports will sell mostly compliant salads (pick off what you must) or have a subway as a restaurant. There is an ap on android, has gate in the name, that can help with restaurants at the larger airports. (It's not that great so I think I deleted it.)