It just can't be done for meal photos -- there's no way of knowing if the mashed potatoes have just a little milk, or two sticks of butter. Or if the tomato sauce is pumped full of sugar or not. Items that are visually identically can have vastly different nutritional profiles.
Not to mention trying to guess what's inside of those dumplings or ravioli...
Not to mention trying to guess what's inside of those dumplings or ravioli...