The fast-food chain said Friday (January 7) it's running short of potatoes.

And that means customers can only have a small portion of fries.

McDonald's Japan say it's down to flood damage near Vancouver and assorted shipping problems.

That includes health-crisis related issues, extreme weather events, and an upsurge in global demand.

As a result, it will only serve small fries for about a month.

It had to take a similar step during December at its roughly 2,900 branches there.

Disgruntled McDonald's customers may not know it, but they're at the mercy of global events.