Well, there are ways to eat cheaply and tastily, though how to do so and also meet bodybuilding goals is beyond me.
When I was younger, poorer, and before starting lifting, I ate for less than $5 per day, and with good tasting food.
One trip to a "Golden Corral" type (a different chain though) restaurant for lunch. The food bar would have been a little over $5, but I learned from a friend it was cheaper to order the steakburger with food bar, and then ask for the baked potato to be omitted, which deducted cost.
Of course that yielded only one (albeit quite large) meal per day, which is not the say to eat for bodybuilding or athletic purposes.
However, correcting for inflation, that would be more than $5 today as this was twenty years ago.
The same basic principle could still be accomplished at CiCi's pizza though for about $5.