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 can't justify this - if you can you should give a lot more credence to this answer).
'it' becomes 'e' ('e' can mean 'electronic' which is similar to 'IT').
'takes' indicates putting letters inside (take can mean to capture or invade).
'lan' going around 'e' is 'LEAN'.
'to get' acts as a 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" .)