hi -
I work with kids who have feeding issues. There are numerous reasons why a child may "pocket" food. e.g. not liking a food, not having enough endurance to chew the food (mouth gets tired). At his age he should be able to manage most table foods without difficulty
Does he only pocket one type of food (e.g. soft foods)? Does he chew any foods or just "suck" on his food? when taking a bite does he move the food from one side of his mouth the other? does he have low muscle tone? Children with lower muscle tone will stuff their mouth because they don’t “feel” the food in their mouth until there is a lot with it.
As far as what can be done to help depends on what the underlying issue is. If it is an issue of not “feeling” (or registering) the food in his mouth I typically “warm” the mouth up (like you would warm up your muscles before a run) using firm (but GENTLE) pressure to the cheeks (moving hands along his face from ears to lips and making lips pucker) – usually making a silly noise while doing this – this should not bother the child. Another way to help is by mixing crunchy foods with softer foods to provided more feedback to where the food is in the mouth (e.g. adding crushed crunchy crackers to the top of mac and cheese).
If this has always been a problem and nothing you do seems to help you may want to consider getting an evaluation by a pediatric therapist that specializes in feeding (either speech or occupational therapy (depends on the area you live in as to which discipline works on feeding).
Good luck!