What makes food go stale? Proximity to the equator, molecules, or whatever?

Question

We live in the Carribean and chips goes stale with quickness

Answer 1

I would guess moisture and how well you close the bags.

Answer 2

starch molecules crystallize when wet, flour gluten molecules and starch molecules. Suspended inside this scaffolding are pockets of carbon dioxide gas that are produced during fermentation by yeast. This creates a foamlike texture.

Answer 3

Well if it's humid outside that adds moisture to your chips. Makes them soft and not very crunchy anymore.