It’s nothing for wild bees to be overweight (5)
I believe the answer is:
obese
'be overweight' is the definition.
(thesaurus)
'it's nothing for wild bees' is the wordplay.
'it's nothing' becomes 'o' (looks like zero - 0).
'for' says to put letters next to each other.
'wild' indicates an anagram.
'bees' with letters rearranged gives 'bese'.
'o'+'bese'='OBESE'
'to' is the link.
(Other definitions for obese that I've seen before include "Grossly fat" , "More than podgy" , "Clinically overweight" , "Unusually fat" , "Extremely portly" .)