Scientists are no longer confused about why pandas put on weight despite their vegetarian diet.

Scientists find reason as to why pandas are so fat

Scientists find reason as to why pandas are so fat

Zoologists have always remained curious as to how the animal manages to stay so rotund when all they eat is bamboo.

However, a study from the Institute of Zoology at the Chinese Academy of Sciences - has shown that giant pandas; gut bacteria changes during bamboo season.

This adaptation in their bodies helps the bears turn more of the daily diet of 24 to 84 lbs of the plant into fat, which could help cope in the times when bamboo shoots are less plentiful.

Guangping Huang, an author of the study said: “"This is the first time we established a causal relationship between a panda's gut microbiota and its phenotype.

"We've known these pandas have a different set of gut microbiota during the shoot-eating season for a long time, and it's very obvious that they are chubbier during this time of the year."

When pandas are born, they are said to be roughly the size of a stick of butter but quickly grow into the large animals we know. According to the WWF, males can get to 300lbs while females reach about 198 lbs.