Transcript Scientific Principles of Nutrition Elizabeth Babson, RD

Scientific Principles of
Nutrition
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The Science of Nutrition
The study of the nutrients and other
substances in foods and the body’s
handling of them.
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Epidemiological studies
Case-control studies
Animal studies
Human intervention/clinical trials
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What Are Nutrients?
Chemical substances obtained from food
Used in the body to provide energy
Used as structural materials and
regulating agents to support growth,
maintenance, and repair of body tissues
May also reduce the risk of some
diseases
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The Six Classes of
Nutrients
Carbohydrates
Vitamins
Lipids
Minerals
Protein
Water
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Energy Yielding vs. NonEnergy Yielding Nutrients
Energy yielding:
Non-energy yielding:
Carbohydrate
Vitamins
Lipids
Minerals
Protein
Water
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Organic Nutrients
A substance or molecule containing
carbon-carbon or carbon-hydrogen
bonds.
Carbohydrate
Lipids
Protein
Vitamins
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Inorganic Nutrients
Not containing carbon or pertaining to
living things
Minerals
Water
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Essential Nutrients
Nutrients a person must obtain from food
because the body cannot make them for
itself in sufficient quantity to meet
physiological needs.
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Dietary Reference Intakes
A set of values for the dietary nutrient
intakes of healthy people in the United
States and Canada, these values include:
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Estimated average requirements
RDAs
Adequate intakes
Tolerable upper intake levels
 http://www.iom.edu/Object.File/Master/7/296/webtablevita
mins.pdf
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Estimated Average
Requirements
The amount of a nutrient required to maintain a
specific body function in half of the population
Example: the amount of calcium needed to
minimize bone loss in later life for half of the
tested population
Formulated by reviewing hundreds of research
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studies
Recommended Dietary
Allowances
 The average daily amount of a nutrient considered
adequate to meet the known nutrient needs of
healthy people
 A goal for dietary intake by individuals
 A point within a range of appropriate and reasonable
intakes between toxicity and deficiency
 Vitamin C: 90mg (males) / 75mg (females)
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Adequate Intakes
 Average amount of a nutrient that appears
sufficient to maintain a specific criterion
 Used as a guide for nutrient intake when an
RDA cannot be determined
 AI relies more on scientific judgment than
evidence
 Vitamin D: AI-5 ug (adults 19-50yo)
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Tolerable Upper Intake Level
 The maximum amount of a nutrient that appears
safe for most healthy people
 Beyond this amount there is an increased risk of
adverse health effects
 Useful in guarding against overconsumption
particularly with supplement usage
 Vitamin A : UL-3000 ug ; Vitamin C: UL-2000 mg
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New Dietary Guidelines…2000
What is a "Healthy Diet"?
The Dietary Guidelines describe a healthy
diet as one that
• Emphasizes fruits, vegetables, whole grains,
and fat-free or low-fat milk and milk products;
• Includes lean meats, poultry, fish, beans, eggs,
and nuts; and
• Is low in saturated fats, trans fats, cholesterol,
salt (sodium), and added sugars.
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Dietary Guidelines
• Grains-eat at least 3 oz of whole grain cereals, breads,
crackers, rice or pasta daily
• Vegetables-eat more dark-green veggies like broccoli,
spinach, and other dark leafy greens; eat moreorange
veggies like carrots and potatoes; eat more dry beans
and peas like pinto, kidney, or lentils
• Fruits-eat a variety of fresh, frozen, canned or dried fruit,
go easy on fruit juices
• Milk-go low-fat or fat-free when you choose milk
products; if you don’t or cant consume milk, choose
lactose-free products or other calcium sourcessuch as
fortified foods and beverages
• Meat & beans-choose low-fat or lean meats & poultry;
vary protein, choose more fish, beans, peas, nuts &
seeds
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Dietary Guidelines
• Tips to help you:
• Make ½ your grains whole
• Choose whole or cut fruit instead of juice (fiber)
• Not all fats = bad-differentiates btwn solid fats (sat &
trans fats) & fat-containing oils (healthier)
• Choose lean meat cuts, and remove skin before eating
• Vary protein choices by eating more fish- rich in omega 3
f.a. like salmon, trout, herring-and make more dishes out
of dry beans or peas instead of animal proteins
• Make exercise fun by varying physical activities and
doing with friends. Walk more, drive less.
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Healthy People 2010
• Includes 28 core focus areas
• Nutrition and Overweight is one of those
areas
• See text p23
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Food Guide Pyramid
A guide to daily food
choices
• http://www.mypyramidgov
• http://www.healthierus.gov
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