Hey @BroForceFive, welcome to the Forums!
There are a couple other posts that explain all the changes with the latest update and the thrall leveling system that I’ll point to you real quick…
https://forums.funcom.com/t/follower-leveling-system-and-follower-limit-now-with-added-faq/92642/2
But, to your specific question, NO, they do not need to eat food to live. There is no ‘maintenance’ requirement that has been reintroduced. However, thralls and pets will eat food to help the heal if they have taken damage. See their preferred food in their inventory - different food will have higher health-per-sec. Also, on the thralls, different foods consumed will get them different bonuses to their chance to level up in a particular stat.
Hope that helps, and good luck!