Substances that nourish the body may be classified as follows:

/ (a) Starch
/ Carbohydrates \ (b) Sugar
Energy Givers " Fats
\ Protein

[Footnote 59: Carbohydrates also include cellulose. But because cellulose does not yield any appreciable amount of energy, it is not listed with starch and sugar.]

/ Complete Proteins
/ Protein
Body Builders \ Incomplete Proteins
\ Ash

/ Ash
Body Regulators " Water / (a) Fat-soluble A
\ Vitamines " (b) Water-soluble B
\ (c) Water-soluble C

[Footnote 60: "So little is known regarding the chemical composition of vitamines that it is difficult to classify them. Since the three food essentials termed as fat-soluble A, water-soluble B, and water-soluble C are individual substances and very different in character, it may be that they will be classified later as three separate foodstuffs. It could then be said that there are eight foodstuffs."]

Make lists of foods rich in:

(1) Water. (2) Ash. (3) Carbohydrates. Subdivide foods rich in carbohydrates, into foods rich in (a) sugar, (b) starch, (c) cellulose (i.e. bulky foods). (4) Fats. (5) Protein. Indicate those foods that contain complete proteins and those that contain incomplete proteins. (6) Vitamines. Subdivide foods rich in vitamines into foods rich in fat-soluble A, water-soluble B, water-soluble C.

Explain why certain foods are contained in two or more lists.