If you are hungry and wants to eat tasty foods then visit the famous Manek Chowk after 9 PM (Before that it is a bullion, commodities and general market).
You will get Dosa, Idli, Sandwich (ICE-CREAM SANDWICH TOO), Panipuri, Bhaji-pau, Pulav, Ragda-petis, Fafda, Cholafali, Chevda, Barbecue, Pan, Buttermilk, Lassi, Bhel, Kulfi, Mouth Freshner (Mukhvas) and what not.
Just visit once if you are in AHMEDABAD.
From 9 PM to 1 AM in the morning you will have opportunity to enjoy the food.