It can depend a lot on why he's frustrated. If its because he is unable to communicate, then a time out might not solving the problem. He might need something else to help him reset to positive behavior. Learning to say "I'm angry right now" is pretty empowering. If he has balance enough to stomp one foot without tipping over, you might give him that option if he needs to show you how he feels. I put toys in time out too. Anything which gets used in a way that is known to be against the rules goes into time out for a day (or longer as they get older). Toys which he can hit and throw can also give him a positive outlet for playfully bad behavior. The food thing can have a lot of reasons too, sometimes it's experimental (peas splat differently than eggs), sometimes it's out of dislike. Sort out which why will help you redirect or stop it.