It’s Fat Bear Week, which means one thing for the 16 Alaskan brown bears competing for the title of heavyweight champion: bigger really does mean better.

The annual contest begins on Sept. 22, the first day of fall, with voting for the carb-loading contenders open to the public until Sept. 29.

Fat Bear Week is a bracket-style, single-elimination tournament with daily rounds to whittle down the field.

This year’s contest features five bear families, two subadults, four single adult females and five adult males who call Alaska’s Katmai National Park home. Among them is last year’s reigning champion, who is fittingly named Chunk, weighing in at approximately 1,200 pounds.

The bears will be streamed live all week, so viewers can catch a glimpse of the rotund foragers in their natural habitats, including at Brooks Falls where they are often seen catching bountiful salmon and taking naps as they fatten up ahead of hibernation season.

Voters are asked to judge each bear’s before-and-after shots from late spring to early fall based on how successful a bulking season they have. The bear they do not vote for in a pairing risks being eliminated.

This year’s competition has the most beefed-up cub competitors it’s seen in a while, Park Superintendent Mark Sturm explained.

“There are more cubs at Brooks Camp this year than have been seen in a long time,” he said. “A new generation of fat bears is taking shape, and they’re off to a strong start. We’re excited to watch them grow and learn as they prepare for winter in Katmai’s incredible ecosystem.”

Last year, over 1,700,000 votes were cast from more than 100 countries before Chunk took home the title, according to the National Park Service.

While the competition is all fun and games, stored body fat is what fuels the bears’ abilities to hibernate during frigid winter months, during which time they don’t eat, drink, urinate, or defecate, meaning they have to pack on the pounds to survive six months without eating.

Fat Bear Week began as a one-day event in 2014 when then-park ranger Mike Fitz was scrolling through comments on the explore.org live feed of Brooks Falls and saw a bear cam fan post two images of the same bear- one from June and one from September.

Shocked by the difference, he started brainstorming ways to highlight the radical changes a bear goes through over the span of several months, which led to the creation of Fat Bear Tuesday, a one-day Facebook event where votes were cast with likes.

Vote for the fattest and most winter-ready bear at fatbearweek.org.