Sickness moving one indeed to eat right, being concerned with nutrition (10)
I believe the answer is:
alimentary
'concerned with nutrition' is the definition.
(I've seen this in another clue)
'sickness moving one indeed to eat right' is the wordplay.
'sickness moving' becomes 'aliment' (I can't explain this - if you can you should believe this answer much more).
'one indeed' becomes 'ay' ('ay' and 'aye' can mean yes).
'to eat' means one lot of letters goes inside another.
'right' becomes 'r' (common abbreviation).
'ay' placed around 'r' is 'ary'.
'aliment'+'ary'='ALIMENTARY'
'being' is the link.
Can you help me to learn more?
(Other definitions for alimentary that I've seen before include "providing nourishment" , "of food" .)