Yes, I understand how easy it is to ignore everything and eat what we want!
It CAN make a difference as for conditioners. You don't want a heavy conditioner on fine hair as those rich like that are meant for deep conditioning of damaged and overprocessed hair. As I said, I am not sure where you are in this world and what products are available.
In U.S. Garnier, John Frieda and some Alberto-Culver products like TRESemme' (I even like the Aussie brand products) are good for those found in department/discount stores. If you live elsewhere in this world, ask your stylist. Naturally, he/she will recommend salon products which are GREAT for the hair as they are special formulated. However, if you don't want to invest that much, prompt them to tell you about some NON-salon conditioners you can buy in your stores.
GOOD LUCK!!!