Many people struggle to keep the pounds off during the dark winter months, but there are some who lose up to a third of their body weight in the cold season.
For them, size matters – and the fatter you are, the better.
Which is why a bear thought to weigh as much as nearly eight men is being celebrated in an annual battle of heavyweights in Alaska.
A salmon-chomping bruin named 747, like the jetliner, has been crowned the fattest bear of the year, winning the popular vote out of 12 chubby contestants.
The bear, one of more than 2,200 roaming Alaska’s Katmai National Park and Preserve, was victorious after a week of online polling during the park’s Fat Bear Week.
Park chiefs estimate that 747 weighs in at more than 1,400 lbs (635kg) – that’s 100 stone, or 7.6 times the weight of an average man in the UK.
Brown bears in Alaska need to eat as much as they can in summer to accumulate fat to survive, because they lose a third of their weight during hibernation when they do not eat or drink. They can grow to at least 1,000lb from feasting in the warm months.
Adult males need to be large to dominate the best fishing spots and secure a mate. Female bears need to gain weight for their own survival, as well as to support the birth and growth of cubs.
So Fat Bear Week celebrates the “survival of the fattest”, as the park service puts it.
The event pits 12 bears against each other, allowing bear fans to compare photos of the animals and vote for their favourites.
Bears gorge on the most easily obtainable rich foods they can find. In Katmai park, that means salmon.
Voters are also asked to donate towards the protection of the park’s bears.
Park bosses say 747 “really packed on the pounds, looking like he was fat enough to hibernate in July and yet continuing to eat until his belly seemed to drag along the ground by late September”.
Katmai, a 4 million-acre park sprawling over mountains, lakes, streams and coastline, has the world’s densest population of brown bears, the coastal version of grizzlies.
Visitor numbers were cut by up to nine-tenths this year, and salmon were plentiful.
“The combination of the big salmon run and fewer people, this has really handed the river to the bears,” said Naomi Boak, of the park.