Maybe not the best guide, someone usually posts better, but here's 
a guide with quite a few options for eats and drinks.

Eat & Drink | Explore | Downtown Indianapolis (downtownindy.org)

Whatever you do, do not go to Weber Grill. You might be ahead of me in line and cause me to have to wait longer for my delicious meatloaf that I look forward to all year :)

This is the second time I have seen a link to that guide and excitedly clicked it only to be like "seriously, an unannotated list of restaurants in Indianapolis?  Is this a webpage from 1996?"  I do grant it would probably be useful if I wanted to look at options before the convention started but damn, otherwise, there really should be a better guide out there somewhere. 

Here's an interesting vegan restaurant that's about a mile north of the ICC:

Black Leaf Vegan Cafe

I know what you mean about needing a better guide, though. I did a quick google search, and all I could find were recommendations and reviews from before the pandemic. :(
 

Yeah for real, a lot has changed since 2019.  This is part of why I have dedicated myself to staying in a different downtown hotel every time I go to Indianapolis for any reason, because I want to try to experience everything post-pandemic so I can build up my own library of recommendations in lieu of any authoritative sources, haha.