Pandas are picky eaters, eating mostly bamboo and not a lot of fat.
Despite that, the bears are huge, and scientists say they now know why
The creatures appear to have evolved to get the most out of what they do eat.
Gut bacteria in pandas change in late spring and early summer when bamboo is at its most nutritious — while it’s sprouting protein-rich green shoots.
The bacteria makes the bear gain more weight and store more fat.