Chapter 4 Nutrition
PE 254
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Nutritional Requirements:
Components of a Healthy Diet
• 45 essential nutrients
▫ Proteins, Fats, Carbohydrates, Vitamins, Minerals
and Water.
• Fuel potential. Kilocalories (kcalorie).
 1 Kcalorie = amount of heat it takes to raise the temperature of
1 liter of fluid 1 degree of centigrade.
 2000 kcalorie or calories per day meets a person’s needs.
 3 supply energy
 Fat = 9 calories per gram
 Protein = 4 calories per gram
 Carbohydrates = 4 calories per gram
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Proteins
• Forms muscle, bone, blood, enzymes,
hormones and cell membrane.
▫ Twenty common amino acids
 Nine essential amino acids.
 Eleven nonessential amino acids
▫ Complete proteins provide all essential amino
acids (e.g., meat, fish, poultry, eggs, milk, cheese,
and soy).
 Most plant proteins are incomplete (e.g., peas,
beans, and nuts).
▫ Recommended amount
 0.8 gram per kilogram of body weight (0.36g
per pound)
 10-35% of total calorie intake
 Average is 15-16%
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Fats or Lipids
• Most concentrated source of energy
▫ stored energy and provides insulation and support
for body organs
▫ Two fats
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 Linoleic acid (unsaturated fatty acid)
 Alpha-linoleic acid (polyunsaturated fatty acid)
Triglycerides - glycerol molecule with 3 fatty acids
Saturated Fat (solid at room temperature)
Mono-unsaturated
Poly-unsaturated
Hydrogenation (H+ + unsaturated fat)
Trans fatty acids
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Fats and Health
• Cholesterol
*required for synthesis of cell membranes,
vitamin D, and hormones
▫ High Density Lipo-Protein (HDLs) – good
cholesterol; transport cholesterol out of
arteries
▫ Low Density Lipo-Protein (LDLs) – bad
cholesterol; transport cholesterol to organs
and tissues, causing fat deposits on arterial
walls
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Chapter 9
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Carbohydrates
• Supply energy for the body cells
• Two groups
▫ Simple Carbs: One or two sugar units
 Fruit, sugar, honey, malt (e.g., barley or wheat), and milk
▫ Complex Carbs: Multiple sugar units
 Starches and fiber
 Grains – wheat, rye, rice, oats, barley, and millet
(white grains)
 Legumes – dry beans, peas, and lentils
 Tubers – potatoes and yams
▫ Digestion
 Mouth and small intestines
 Break down to glucose
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Refined Carbohydrates Versus
Unrefined (Whole) Grains
• All grains before processing
▫ Inner layer, germ
▫ Middle layer, endosperm
▫ Outer layer, bran
• During processing
▫ Germ and bran are removed leaving just the
starch of the endosperm
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Glycemic Index and Glycemic Response
• Insulin and glucose levels
• Quick rise in glucose and
insulin levels = high glycemic
index
▫ Eating high glycemic index
foods may increase appetite
▫ May increase risk of diabetes
and heart disease
▫ Unrefined grains, fruits,
vegetables and legumes –
relatively low glycemic index
http://www.glycemicedge.com/glycemic-index-chart/
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Recommended Carbohydrate Intake
• Average American – 200-300 grams
• 130 grams needed to meet the body’s
requirements for essential carbohydrates
• Adults – 45-65% of total daily calories or
225-325 grams
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Fiber
• Food and Nutrition Board
▫ Dietary fiber nondigestible carbohydrate that is
present naturally
▫ Functional fiber nondigestible carbohydrate that
has been isolated or synthesized
▫ Total fiber is the sum of both
• Sources
▫ All plant substances
• Recommended intake
▫ 38 grams for adult men
▫ 25 grams for adult women
▫ Needs to come from foods not supplements
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Vitamins
• Organic (carbon-containing) substances
required in small amounts to promote
specific chemical reactions (catalyst) within a
living cell.
• Thirteen vitamins:
▫ Four Fat Soluble: A, D, E, and K.
▫ Nine Water Soluble: C and 8 B-complex vitamins. Thiamin
(B1), Riboflavin (B2), Niacin (B3), Pyridoxine (B6), Folate, B12, Biotin and Pantothenic acid.
• Sources:
▫ Human body does not manufacture most vitamins
▫ Abundant in fruits, vegetables and grains
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Minerals
• Inorganic compounds.
• Helps to regulate body functions, aid in
growth, maintenance of body tissues, and a
catalyst for energy release.
• 17 essential minerals.
▫ Major minerals - 100 milligrams or more.
 calcium, phosphorus (e.g., additives), magnesium
(e.g., nuts), sodium, potassium and chloride (e.g.,
additives, such as sodium chloride).
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Water
• Composed of about 50-60% water
• Can live up to 50 days without food , but only
a few days without water
• Water and other beverages make-up 80-90%
of your daily water intake
• Men – 3.7 total liters of water, with 3.0 liters
(13 cups) coming from beverages
• Women – 2.7 total liters of water, with 2.2 (9
cups) coming from beverages
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Other Substances in Food
Antioxidants –
▫ Reduction in cancers
▫ Vitamin C & E, selenium (e.g.,
nuts), carotenoids
• Phytochemicals
▫ Soy foods may help lower
cholesterol levels
▫ Cruciferous vegetables render
some carcinogenic compounds
harmless
▫ Allyl sulfides (garlic and onions)
boosts the cancer-fighting
immune cells
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USDA’s MyPyramid
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Vegetarians
• Possible reasons:
health
environmental concerns
financial considerations
ethics or religion
• Types:
▫ Vegans (no animal products at all)
▫ Lacto-vegetarians (milk and
cheese)
▫ Lacto-ovo-vegetarians (eggs and
milk)
▫ Partial vegetarians,
semivegetarians, and
pescovegetarians (eggs, dairy
products, poultry and seafood)
• A food plan for vegetarians
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Vitamin B-12
Vitamin D
Calcium
Iron
Zinc
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Protecting Yourself Against Foodborne Illness
• Causes of Foodborne Illnesses
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Campylobacter jejuni
Salmonella
Shigella
Escherichia coli
Listeria monocytogenes
Staphylococcus
Clostridium botulinum
Norovirus
Campylobacter jejuni
Staphylococcus
• Preventing and treating foodborne illnesses
• Environmental Contaminants and organic
foods
• Food Allergies
Escherichia coli
Salmonella
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Food Allergies and Food Intolerances
• Food allergies
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Reaction of the body’s immune system
Affect 2% of the adult population
4-6% of infants
90% of food allergies
 Cow’s milk, eggs, peanuts, tree nuts, soy, wheat,
fish, and shellfish
• Food intolerances (metabolic problems)