It seems that consumable food doesn't despawn in the latest patch, so your problem is likely the same as mine. Ants are hoarding food-bits near or in their anthills. I went near the black anthill and found around 300+ pieces of billy dogs, and at least 150 pieces of apple bits. I suggest you run to the location i've given a red ant marker in the circle of my screenshot, and see if there's food in the water here, then clear it out by either trashing it, or take it back to your base. I did this and went from 10 fps to 100+ fps after clearing that area. Hope this helps