Do People Selling Prepared Foods Have Health Department Approval?

This is a topic that has been requested by a reader.

Does the Health Department or any other governmental agency inspect, regulate and sanction the sell of all prepared foods sold in the county and state? 

The question arises from the fact that there are a number of sellers of prepared foods, (home canned goods, baked goods, smoked and barbecued meats, cheeses etc.) that would be required to have Health Department inspections were they in a store or restaurant.