In selecting a meal most individuals do not
consciously select protein, minerals, and
vitamins. Instead, they think in terms of
foods or groups of foods that, combined each
day, furnish as nearly as is now known what
the body needs for healthful living, or, as we
say, an ''adequate diet.” Knowledge of food
composition is necessary to interpret food
needs in terms of food groups.
Chemically, foods are composed largely of
carbon, hydrogen, and oxygen, the elements
making up the greater portion of all organic
foods, but in addition they contain many other
elements in varying proportions. Nitrogen,
sulfur, and phosphorus are additional ele¬
ments present in proteins. Of the mineral
elements, calcium, iron, and iodine have im¬
portant functions in the body, and agreement
has been reached as to the amounts required.
Other elements are known to be necessary,
and are present in traces in natural foods so
as to offer no serious problem of selection
when diets are adequate in other respects.
In evaluating foods from the point of view
of nutrition, their composition is ordinarily
stated in terms of the basic food constituents
j
of similar composition and function in the
body. These are carbohydrates, fats, protein,
water, and the mineral salts or ash, the por¬
tion which would remain if the food were
burned. To plan adequate diets we must
know the amounts of these constituents in
different foods and the function each serves.
Carbohydrates. Carbohydrates are the
simplest of the organic food constituents.
Carbohydrates include the sugars and the
starches. All the food carbohydrates of any
importance, except lactose, the sugar in milk,
are of plant origin. Carbohydrates contain
only the three elements carbon, hydrogen,
and oxygen. They burn completely in the
body, and in doing so give off energy, yielding
carbon dioxide and water.
Fats. Fats also are organic foods com¬
posed of carbon, hydrogen, and oxygen.
They contain a smaller proportion of oxygen
than the carbohydrates. This means that
more of the carbon is in an unoxidized form,
so that fats are a more concentrated source
of energy than carbohydrates. Under normal
conditions fats burn completely in the body,
yielding carbon dioxide and water. Fats
occur naturally in varying amounts in most
foods. When in liquid form they are called
oils. Solid food fats in relatively pure form,
such as butter and lard, are largely of animal
origin, and oils are obtained from the seeds
of plants. (See page 136.)
Proteins. Proteins are organic compounds
containing phosphorus and sulfur in addi¬
tion to carbon, hydrogen, oxygen, and nitro¬
gen. Proteins are essential in body building
as a source of the amino acids, the building
stones of proteins. Proteins may burn in the
body, yielding energy. They always leave an
organic residue containing nitrogen. This
residue is excreted in the urine largely as urea.
Page 4
Presented as published in 1935. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
AI-modernized reading of the original text
In selecting a meal most individuals do not consciously select protein, minerals, and vitamins. Instead, they think in terms of foods or groups of foods that, combined each day, furnish as nearly as is now known what the body needs for healthful living, or, as we say, an ''adequate diet.” Knowledge of food composition is necessary to interpret food needs in terms of food groups.
Chemically, foods are composed largely of carbon, hydrogen, and oxygen, the elements making up the greater portion of all organic foods, but in addition they contain many other elements in varying proportions. Nitrogen, sulfur, and phosphorus are additional elements present in proteins. Of the mineral elements, calcium, iron, and iodine have important functions in the body, and agreement has been reached as to the amounts required. Other elements are known to be necessary, and are present in traces in natural foods so as to offer no serious problem of selection when diets are adequate in other respects.
In evaluating foods from the point of view of nutrition, their composition is ordinarily stated in terms of the basic food constituents
j
of similar composition and function in the body. These are carbohydrates, fats, protein, water, and the mineral salts or ash, the por¬ tion which would remain if the food were burned. To plan adequate diets we must know the amounts of these constituents in different foods and the function each serves.
Carbohydrates. Carbohydrates are the simplest of the organic food constituents. Carbohydrates include the sugars and the starches. All the food carbohydrates of any
importance, except lactose, the sugar in milk, are of plant origin. Carbohydrates contain only the three elements carbon, hydrogen, and oxygen. They burn completely in the body, and in doing so give off energy, yielding carbon dioxide and water.
Fats. Fats also are organic foods composed of carbon, hydrogen, and oxygen. They contain a smaller proportion of oxygen than the carbohydrates. This means that more of the carbon is in an unoxidized form, so that fats are a more concentrated source of energy than carbohydrates. Under normal conditions fats burn completely in the body, yielding carbon dioxide and water. Fats occur naturally in varying amounts in most foods. When in liquid form they are called oils. Solid food fats in relatively pure form, such as butter and lard, are largely of animal origin, and oils are obtained from the seeds of plants. (See page 136.)
Proteins. Proteins are organic compounds containing phosphorus and sulfur in addition to carbon, hydrogen, oxygen, and nitro¬ gen. Proteins are essential in body building as a source of the amino acids, the building stones of proteins. Proteins may burn in the body, yielding energy. They always leave an organic residue containing nitrogen. This residue is excreted in the urine largely as urea.