My first two dogs (Golden Retriever then GSD) had no problem with me being around or touching their food.
Around 5 or 6 yrs old, Yukon decided to start lunging at me anytime I got within 2-3ft while he was eating. Not acceptable behaviour at all!
To nip that in the butt, I upped the NILIF, and started feeding him (would hold his bowl) where he usually enjoyed pets and cuddles. If he wanted to be pet or cuddle that would be done where I fed him. He stopped that behaviour about a week later.
(I was on an emotional roller coaster at the time. I think he found that too unpredictable so started setting his own rules.) He is perfectly fine now.
I typically don't mess with my dogs while they eat. (It's their food, I'm not going to eat it.) I don't have many guest over, and no small kids to think about.
All I expect is for them to allow me to place extra bits in their bowl, take it away if needed and allow me to take things out of their mouth that they shouldn't have. (cooked bones mostly)
I have never had a dog who was possessive of their toys.
Anita & 10 1/2 yr old Yukon
R.I.P Amber & Cisco:
"Goodbye may seem forever
Farewell is like the end
But in my heart's a memory
And there you'll always be."