To build up a complete diet we have to know how many of these items are present in a given food and also how much of each is there.
Now, cereals are much alike in what they contribute to the diet.

In comparing them we are apt to emphasize their differences, much as we do in comparing two men.

One man may be a little taller, a little heavier, have a different tilt to his nose, but any two men are more alike than a man and a dog.

So corn has a little less protein than wheat and considerably less lime, yet corn and wheat are, nutritionally, more alike than either is like sugar.
None of the cereals will make a complete diet by itself.

If we take white bread as the foundation, we must add to it something containing lime, such as milk or cheese; something containing iron, such as spinach, egg yolk, meat, or other iron-rich food; something containing vitamines, such as greens or other vitamine-rich food; something to reenforce the proteins, as milk, eggs, meat, or nuts.