Nutrition for nursing
Dr. Fahad Aldhafiri
Protein
• Proteins are essential nutrients for the human body.
• They are one of the building blocks of body tissue,
and can also serve as a fuel source.
• As a fuel, proteins contain 4 kcal per gram, just like
carbohydrates and unlike lipids, which contain 9 kcal
per gram.
Amino acids (AA)
• AA are the basic building blocks of all protein.
• AA are organic compounds made from carbon,
hydrogen, and oxygen atoms plus a nitrogen
component, which distinguishes them from the
other energy nutrients.
Classification of AA
• Essential amino acids: AA that cannot be
made by the body; they must be consumed
through food.
• Non- essential amino acids: AA the body can
make if nitrogen and other precursors are
available.
• Note: the terms of essential and non-essential
refer to whether or not they must be supplied
by the diet, not to their relative importance:
all 20 AA must be available for the body to
make proteins.
Digestion
Functions
• Protein is a nutrient needed by the human body for
growth and maintenance.
• Protein can be found in all cells of the body and is
the major structural component of all cells in the
body, especially muscle. This also includes body
organs, hair and skin. Proteins are also used in
membranes.
• When broken down into amino acids, they are used
as precursors to nucleic acid, co-enzymes, hormones,
immune response, cellular repair, and other
molecules essential for life. Additionally, protein is
needed to form blood cells.
• Burned for energy: normally the body uses very little
protein for energy.
• Converted to fat (Lipogenesis): protein is
converted to fat only when it is consumed in
excess of need. The carbon fragment (acetyleCoA) undergoes lipogenesis to form fatty
acids.
• Converted to glucose.
Protein in food
• Complete proteins: provide all nine essential
amino acids.
Sources: all animal sources of protein (meat,
fish, poultry, eggs, milk and diary products)
• Incomplete proteins: provide all essential
amino acids but have one or more
limiting amino acids.
Sources: all plant proteins (grains (rice,
bread…), legumes, nuts and vegetables)
Intake recommendation
• 0.8 g/kg: 80 kg -------> 80 X 0.8 = g/kg
• 10 – 15 % of total calories