Outside of the apartment in the Gun Store, Hank will give you advice about a Grocery Store not far from that location. There are 2 Thinmen as soon as you get inside. Upon checking the cash register, "You" will state that there is no use of currency anymore. Past the Thinmen and the Register, there is a box, similar to the one that the MWWAB wears. It has a cat comic and food. Visit it every day and something new comes in it. Varying food.
You's mental health is presumed to have no effect on what foods spawn in the cardboard box every day. At the time of writing, the following foods are known to appear in the box:
Due to awkward placement of hiding spots and their proximity to the Thinmen, the most reliable strategy is to restock on Rotting Meat and place two pieces near the entrance when the first Thinman is far away enough for You to make it to the first hiding spot without being noticed. Hide and wait for the other Thinman to pass by and then make a break for the cardboard box. Having looted the store, drop two more pieces of rotting meat, hide one more time and wait until the way back is clear.
The cardboard box You gets food from exhibits near-perfect similarity to those found lying at The Director's feet and on The Man Who Wears A Box's head, further reinforcing the Nurture theme present in the game.