Let me tell you from personal experience: do not eat sushi, taco dip or anything Indian before you practice yoga. It just doesn’t suit your belly well!
So... what should you eat before class?
I believe you should keep it simple. Nothing with too much heavy flavor that you will be tasting later in downward dog (especially if your power teacher loves core work) Here is a list of simple foods that I would eat an hour or so before class. If you’re pressed for time, and eating on the go, almonds are always a great choice. Just make sure to down them with water so you’re not dehydrated later!
Carrots, peppers & other light veggies
Small piece of dark chocolate
Toast with butter (or vegan butter)