Im not certain if he does know of the various food programs in our area but I will definitely tell him. When he was still married to his wife they did okay financially and its because of various problems that he moved out with the children and is taking on a Mister Mom role full-time.
As I had worked for but continue to volunteer at various not for profits in the region I will compile a list of all the resources and help that is available.
Our local soup kitchen has it where you can volunteer to help serve the hot food and then they INSIST that you eat a meal yourself. Perhaps this will be a good segway to get him comfortable.
I would defintley consider joining him in line while he gets his first free box as it is a little "scary and uncertain" when you do it the first time. At the very least he'll have a familiar face to be there with him and a fun, "see's the glass as half full" kind of guy at his side.
"Life is like an elevator: it has its up and downs - but remember its up to you to make the most of each floor"