$60 a day? Jesus christ. That would be the like getting food delivered to you for breakfast lunch and dinner. Have you ever lived on your own? I'm sorry but the only source I can give you is comparative stuff like this where two people are eating 3 meals a day for $125 a week and that's with frozen food which is expensive itself. Also in that post is this commend where they're feeding a family of 4 for $100 a week. Literally carbs, vegetables and sales will take you so far as long as you cook everything yourself.

Here (PDF warning) is an economic paper talking about how even though the price of the 5 main types of meat are inelastic, and the income flexibility (the ability to spend their money freely) decreases, people on the lower end of wealth buy more meat than those on the higher end even though they're in the least financially capable position. Kinda straying from the point but what I'm trying to show with the first paper I found that kinda worked is that poor people buy meat even though economically they really shouldn't.

That's enough for a comment on /r/Livestreamfails tbh. I know plenty of people who live on $10 a day or less because they buy in bulk, get vegetables and pay attention to sales. You're right in that it doesn't matter at all, but spending some American's entire yearly salary on food it's pretty ridiculous to call it modest.