The days of letting visitors throw marshmallows to the animals are mostly history at zoos around the country, replaced by a growing focus on diet and nutrition that parallels the fitness craze in humans.
And thanks to mounting research on wild animals' food needs, today's zoo staffers are trying new feeding tricks to keep their lions and tigers and bears healthy and happy.
Avoiding obesity is part of the program.
Like humans, many zoo animals "like the good stuff. They like the sugary, high-fat food, and they're not moving as much as they're genetically programmed to," said Jennifer Watts, staff nutritionist at suburban Brookfield Zoo, west of Chicago.