Selective breeding has made the fruit we eat so full of sugar, Melbourne Zoo has had to wean its animals off it.

Fruit is vital in human diets, and we all need to eat more. But at the zoo, keepers found fruit-heavy diets were making some animals obese – and rotting their teeth.

Yum yum yum. Credit:Eddie Jim

"The issue is the cultivated fruits have been genetically modified to be much higher in sugar content than their natural, ancestral fruits,” says Dr Michael Lynch, the zoo’s head vet.

"It's interesting. After doing a lot with nutrition here, I tend to eat less fruit."