CHATTANOOGA (WRCB)  --  The warehouse at the Chattanooga Area Food Bank was buzzing with volunteers Tuesday, all of whom were eager to feed 20,000 hungry families.

However, the food supply is running low.

"Within the last couple of months I have noticed we're kind of low on a lot of things," says volunteer, Debra Owens.

Owens has volunteered at the food bank since 2010, and spends most of her time packing boxes.

"One of the things that we're running low on is peanut butter," she says.

Officials blame the rising cost of food and the increase in need for the shrinking inventory.

The food bank also relies heavily on grocery store donations. But when the area Food Lions closed, the donations stopped coming. 

"They did a lot of perishable foods, like produce and dairy and meat," says Chattanooga Area Food Bank President Clare Sawyer.  

Sawyer says Channel 3's annual "Share Your Christmas" food drive can only last so long.

"What we get at Christmas and over the holidays begins to dwindle. Right now we really look for the postal drive to fill that gap," Sawyer says.  

However, this year that gap is a little bigger and without a reminder by mail like years past, officials fear postal donors may simply forget.

"The postal drive has always been our salvation," Sawyer says.  

Last year the Stamp Out the Hunger postal food drive brought in 60,000 pounds of food.

Organizers are hoping for the best this year.

"Either hang it on the mailbox, or put it right below, and they will pick it up when they deliver the mail," explains Sawyer.

The postal food drive is Saturday, May 12.

Organizers are asking for donations of peanut butter, tuna and canned meat.

If you miss the mail carrier, you can drop off food donations at any post office.

They'll also pick up food on Monday.

Click here for more on Stamp Out the Hunger food drive