From this point of view there is no such thing as a "meat substitute." But, nutritionally speaking, meat is only one of many; undeniably a good source of protein, but no better than milk or eggs.

A lamb chop is a very nice item on a bill of fare, but the protein it contains can be secured just as well from one large egg, or two level tablespoonfuls of peanut butter, or one and one-fourth ounces of cheese; or a part of the time from a quarter of a cup of dried navy beans or a little less of dried split peas.
Meat is highly regarded as a source of iron; but, again, it has no monopoly of this important building-stone in the house of diet.

The eggs, or peas, or half the beans mentioned above would any one of them furnish more iron than the lamb chop, while a quarter of a cup of cooked spinach or a small dish of string beans would furnish quite as much.

Besides green vegetables, fruit, and the yolk of egg, cereals are a not inconsiderable source of iron.

A man would have adequate nourishment for a day, including a sufficient supply of iron, if he were doing only moderate physical labor, from one pint of milk, one and one-half pounds of whole wheat bread, and three medium-sized apples.