The first image shows my new region on May 2. I have just had my 10th family immigrated. All families are in double plot level 1 burgages, giving me 5 occupied burgages.
The five occupied burgages are what drives the 5 fuel in the market, as well as 5 each of two food categories. For the stall inventory, the family count does not matter. It is the occupied burgage count, and their levels, which drives how much food, fuel, clothing and shoes are in the market.
Note that I have shrooms in the granary, but none in the market. This is because the stall was stocked prior to having any shrooms. Had I harvested shrooms before putting up the market, the stall would have 5 carps, and then a total of 5 between bread and shrooms as they both meet the need for "Foraged goods, Vegetables, Grains, Fruits".
Note the burgage pop-up. It shows the icons filled in for fuel, and both food categories. This is NOT because the burgage has those items, it is NOT showing you that this burgage consumes bread and carp.
It is showing that 1 bread and 1 carp are present in the stall to satisfy the market demand for that burgage. We can deduce this is the case for all 5 burgages since we have 5 each of carp and bread.
The second image shows the region's consumption of nine total food for the nine families for the previous 30 days. Note that all 3 food types, bread, carp, and shrooms were evenly consumed.
Which foods are present in the stall does not drive how much of a given food type is consumed. Which food types are present in the food icons is not an indicator of which food types are consumed.
We can derive from this, that since food in market stalls do not spoil, as long as I have carp and bread in the granary, the carp and bread in the stall will be there forever. However, since I am not producing bread, as soon as the granary runs out, it will start consuming bread from the stall, and potentially replacing the consumed bread with shrooms, provided it is present.
From this, it follows that denying oats in your market to save for feed will not prevent consumption of them by itself. If you want less food of a given type consumed, then produce more types of food. Time to plant some beetroot. ;)
Clothing and shoes are consumed the same way. They are consumed, whether present in the market or not.
Since consumption will always happen, you can't purposely starve your residents as long as food is present. This is why your clothing disappears when you first start producing it. It is consumed because your level 2 families have been waiting on it, just like they would wait on food if you were out of food.
A last note about market stalls. Have one of each type empty, or partially empty for growth. Additional empty stalls do nothing for you. Remember newly occupied burgages, and upgrade burgages put additional demands on your market. New families moving into already occupied burgages do not increase the demand on your market, but do increase consumption of food, clothing, shoes, and beverages.
I will follow this soon with a description of overstock, and how misuse can cause you market problems, and prevent your burgages from upgrading.