The ornamental design for a lid for foodcontainer, as shown and described.
FIG. 1 is a perspective view of a lid for food container showing our new design;
FIG. 2 is a lower perspective view of the lid for food container;
FIG. 3 is a front view of the lid for food container;
FIG. 4 is a rear view of the lid for food container;
FIG. 5 is a left side view of the lid for food container;
FIG. 6 is a right side view of the lid for food container;
FIG. 7 is a top view of the lid for food container; and,
FIG. 8 is a bottom view of the lid for food container.
The broken lines showing in the figures are included for the purpose of illustrating portions of the lid for food container that form no part of the claimed design.