A refrigerator appliance includes a cabinet which defines a fresh food storage chamber, a frozen food storage chamber, and a variable food storage chamber positioned between the fresh food storage chamber and the frozen food storage chamber. The refrigerator appliance includes a wall which at least partially defines the variable food storage chamber. The wall includes an outer surface facing an ambient environment around the refrigerator appliance and an inner surface positioned opposite the outer surface. The refrigerator appliance also includes insulation extending between the outer surface of the wall and the variable food storage chamber. The insulation includes a plurality of movable segments. The movable segments are movable between a first position and a second position. A thermal conductivity of the wall is greater when the movable segments are in the second position than when the movable segments are in the first position.