Jim McMahon/MapMan®

For brown bears, bigger is better. A bear named Beadnose won this year’s Fat Bear Week contest at Katmai National Park in Alaska. From June to October, bears gain as much weight as possible to get ready to hibernate. Beadnose nearly doubled her weight in three months. She now tips the scales at about 800 pounds.

People from around the country got to witness the weight gain. They watched on the park’s live cams as the bears splashed in a river and dove for salmon. Brown bears eat at least 30 salmon a day. Each fish has about as many calories as 15 cheeseburgers.

The bears also eat berries, plants, and just about anything else they can get their paws on. They can gain up to 6 pounds of fat each day.

In October, park rangers posted before-and-after photos of the bears on social media. People voted for the one that appeared to gain the most weight. Beadnose was the big winner. But getting plump isn’t about winning a contest.

“A bear that doesn’t get fat enough might not survive the winter,” says park ranger Russ Taylor.

Beadnose and the other bears in the park have already begun hibernating. Between late October and early December, bears dig out their dens and settle in. For at least five months, they won’t eat, drink, or go to the bathroom. They’ll get all the nourishment they need from their body fat.

While in hibernation, Beadnose will lose about a third of her body weight. She’ll leave her den much lighter in the spring. Before long, she and the other bears will start fattening up all over again.