Like the years it takes to get slim? (4)
I believe the answer is:
lean
'slim?' is the definition.
('lean' can be similar in meaning to 'slim')
'like the years it takes' is the wordplay.
'like the years' becomes 'lan' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'it' becomes 'e' ('e' can mean 'electronic' which is similar to 'IT').
'takes' is an insertion indicator (take can mean to capture or invade).
'lan' enclosing 'e' is 'LEAN'.
'to get' is the link.
Can you help me to learn more?
(Other definitions for lean that I've seen before include "With no fat; slope" , "The fatless part of the meat" , "List; thin" , "Spare - list" , "Inclination" .)