Thanks for the advice, guys!
I like non fat Greek yogurt but it's hard to find here (I live in a veryyyyy small town). I did find the full fat version, but I'll just wait until they get the lower fat one in stock. I'm guessing regular yogurt isn't the same?
The egg white powder sounds like a good idea! I like making smoothies and shakes.
I also bought some whey protein powder, but I'm hesitant to use it a lot because the kind I bought has a lot of artificial things in it. But I recently used it to make a batch of delicious chocolate banana oat cookies with egg whites (yum)!