As written these are the details of what happens:

If one berry is eaten you fill with juice until you're full or bloated

If you eat two at the same time your skin turns to the berry's color pattern and leaves you at the verge of bursting

Finally if you eat three berries at the same time you will go from slow to fast filling of juice and explode.

Larger species can eat more than three

Average species can eat less than two

Small species can only eat one per day

Species with stretchy skin can eat a as much as they want

Species who specifically eat the berries without it exploding are: anything related to a bird

A variant of the berry is a purplish one that causes you to inflate slowly and forces your body to digest it into fatness