Download Classes of Nutrients

Chapter 1
NUTRITION:
Food for Health
Nutrition Terms
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Nutrition is a science that studies the
interactions between living organisms and
the food they consume.
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Nutrients and energy are provided by food.
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Energy is measured in kilocalories.
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Essential nutrients must be supplied in the
diet.
Copyright 2012, John Wiley & Sons Canada, Ltd.
The Canadian Diet
Past
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Present
more time spent obtaining
food ingredients
more time spent
preparing foods
less variety (consumed
seasonal foods)
family sat together to eat
meals at a leisurely pace
reasonably-sized portions
of food
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purchase convenient and
processed foods
spend less time preparing
meals
more meals eaten outside
of the home (fast food
restaurants)
families not eating
together
larger portions
Copyright 2012, John Wiley & Sons Canada, Ltd.
The Canadian Diet
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Concern in the past was obtaining all the
nutrients needed for good health.
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Concern now is limiting consumption to
prevent obesity and chronic diseases
associated with it.
Copyright 2012, John Wiley & Sons Canada, Ltd.
How Healthy is the Typical
Canadian Diet?
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The Canadian Community Health Survey
(CCHS) shows that the Canadian diet is not
as healthy as it could be.
Approximately 50% of Canadian adults do not
meet the recommended servings for
vegetables and fruit.
Two thirds of Canadians age 30 years or
older do not meet the recommended servings
for milk and alternatives.
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How Healthy is the Canadian
Diet? (continued)
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Many Canadians are not meeting the
recommended intake for grains.
Only in the meat and alternatives group do
Canadians meet the recommended intake.
With the consumption of more processed and
convenience foods, the Canadian population
is consuming more kilocalories, sodium and
fat and fewer nutrients.
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Nutrition-Related Deaths
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Classes of Nutrients:
Macronutrients
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Energy-yielding nutrients include
carbohydrates, proteins and fats.
Energy-yielding nutrients are also called
macronutrients.
Macronutrients are needed in the body in
large amounts each day.
Copyright 2012, John Wiley & Sons Canada, Ltd.
Classes of Nutrients:
Macronutrients
Copyright 2012, John Wiley & Sons Canada, Ltd.
Classes of Nutrients:
Macronutrients
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Macronutrients provide energy to the body.
The amount of energy is measured in
kilocalories or kilojoules, depending on the
country you are in.
1 kilocalorie = 4.18 kilojoules
4.18 kilojoules = 1 kilocalorie
Kilocalorie is abbreviated kcalorie or kcal.
Kilojoule is abbreviated kjoule or kJ.
Copyright 2012, John Wiley & Sons Canada, Ltd.
Classes of Nutrients:
Macronutrients
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Carbohydrates are one type of
macronutrient.
Carbohydrates include sugars and starches.
Fibre belongs to the carbohydrates category
but does not provide energy.
Carbohydrates contain 4 kcalories/gram.
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Carbohydrates,
Lipids and
Proteins
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Classes of Macronutrients:
Lipids
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Lipids are commonly called “fats” or “oils.”
Lipids are a concentrated form of energy.
Triglyceride is a type of fat that is found in
abundance in the body.
Copyright 2012, John Wiley & Sons Canada, Ltd.
Classes of Macronutrients:
Lipids
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Foods high in saturated fatty acids may
promote certain diseases.
Foods high in unsaturated fatty acids may
help prevent certain diseases.
Lipids contain 9 kcalories/gram.
Copyright 2012, John Wiley & Sons Canada, Ltd.
Categories of Macronutrients:
Proteins
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Proteins are required for growth,
maintenance and repair of the body.
Proteins can also supply energy.
Meat, fish, poultry, dairy products,
legumes and grains can provide protein.
Copyright 2012, John Wiley & Sons Canada, Ltd.
Categories of Macronutrients:
Proteins
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Proteins are made up of different
combinations of amino acids.
Proteins provide 4 kcalories/gram.
Copyright 2012, John Wiley & Sons Canada, Ltd.
Classes of Nutrients:
Micronutrients
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Micronutrients provide no energy for the
body but are necessary for proper
functioning of the body.
Micronutrients include vitamins and minerals.
Micronutrients are very important for good
health but are required in small amounts.
Copyright 2012, John Wiley & Sons Canada, Ltd.
Micronutrients (continued)
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Micronutrients can be found in most foods.
Fresh foods are a good natural source of
micronutrients.
Fortified processed foods also supply
vitamins and minerals. Canada allows
fortified foods, in which micronutrients lost in
processing are replaced.
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Classes of Nutrients: Water
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Water is a macronutrient, meaning that it is
required in large amounts.
Water does not provide kcalories.
Water makes up approximately 60% of the
healthy human body.
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Composition of the Human Body
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Functions of Nutrients:
Providing Energy
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Working together, macronutrients and
micronutrients help the body to stay healthy.
Biochemical reactions in the body help to
release the energy contained in carbohydrates,
fats and proteins.
Energy is used to maintain body functions and
fuel physical work.
If more energy is consumed than is needed,
over time body weight will increase.
Copyright 2012, John Wiley & Sons Canada, Ltd.
Functions of Nutrients:
Forming Structures
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Most of the weight of the body is due to
water, fat and protein.
Nutrients help to form and maintain the
shape and structure of the body.
Proteins form ligaments and tendons that
hold bones together and attach muscles to
bones.
At the cellular level, lipids and proteins make
up the membranes that surround cells.
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Regulating Body Processes
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All the reactions that occur in the body are
called metabolism.
The proper regulation of metabolism is called
homeostasis.
Each nutrient plays a role in helping to maintain
homeostasis.
Water helps to regulate temperature.
Protein, vitamins and minerals help to speed up
or slow down metabolic reactions.
Copyright 2012, John Wiley & Sons Canada, Ltd.
Nutrient Intake and Health
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Malnutrition can mean eating too little or too
much of one or more nutrients.
Undernutrition is malnutrition caused by
eating insufficient amounts of energyproviding foods.
Overnutrition is malnutrition caused by eating
an excess of energy-providing foods.
Copyright 2012, John Wiley & Sons Canada, Ltd.
Food Availability
Food availability depends on:
 Geography
 Transportation and mobility
 Available income
 Food storage and preparation equipment
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Cultural and Personal
Background
Health is impacted by cultural and personal
variables such as:
 Religious dietary laws
 Ethnic menu preferences
 Social acceptability
 Personal preference
 Psychological and emotional factors
 Health concerns
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Nutrient Density
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Nutrient density is a measure of the nutrient a
food provides compared to its energy content.
A nutrient-dense diet is a healthy diet.
For example, broccoli is more nutrient-dense
than French fries.
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Nutrient Density
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Choosing a Healthy Diet
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Eat a Variety of Foods
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No one food provides all necessary
nutrients.
Selecting a variety of foods helps the body to
obtain all necessary nutrients.
There are many interactions between foods.
Selecting a variety of foods means you will
provide the fuel the body needs, even if some
of the food interactions are not positive.
Copyright 2012, John Wiley & Sons Canada, Ltd.
Everything in Moderation
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Moderation means all types of foods and
beverages are okay, as long as they are
taken in moderation.
Moderation means not consuming too much
energy, fat, sugar, sodium or alcohol.
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Understanding Science
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Nutrition is a science.
Developing an understanding of the
processes in nutritional science will help us
to understand the relationship between
nutrition and health.
Understanding nutritional processes will help
us to make wise nutrition decisions.
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The Scientific Method
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Advances in nutrition are made using the
scientific method.
The scientific method uses an unbiased
approach to examine the interaction of food,
nutrients and health.
The steps in the scientific method are:
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Observation
Hypothesis
Theory
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The Scientific Method
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What Makes a Good
Experiment?
A well-conducted experiment requires:
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Quantifiable Data
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Appropriate Experimental Population
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Can we measure the information in a scientific manner?
Is the population large enough and pertinent to the study?
Proper Controls
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Can we ensure that the population ate or drank what we
said they did?
Copyright 2012, John Wiley & Sons Canada, Ltd.
What Makes a Good
Experiment?
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Control groups act as a standard of comparison.
Placebos are identical in appearance to the actual
treatment but are of no therapeutic value.
Single-blind study: subjects do not know which
treatment they are receiving.
Double-blind study: neither the subjects nor the
investigators know which treatment is being
received.
The peer review system allows for scientific
interpretation of experimental results.
Copyright 2012, John Wiley & Sons Canada, Ltd.
Types of Nutrition Research
Studies
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Observational studies can include
epidemiology, the study of diet, health and
disease patterns, and correlation.
Human intervention studies are also known
as clinical trials.
Laboratory studies are conducted in
research facilities such as hospitals or
universities.
Copyright 2012, John Wiley & Sons Canada, Ltd.
Identifying Reliable Nutrition
Information
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Does the information make sense?
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For example, can you really lose forty pounds in
one week?
Where did the information come from?
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Information from personal testimony or from one
health care professional is probably not reliable.
Copyright 2012, John Wiley & Sons Canada, Ltd.
Identifying Reliable Nutrition
Information
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Is the information based on well-designed,
accurately-interpreted research studies?
Who will benefit when you purchase this
product?
Has this product stood the test of time?
Copyright 2012, John Wiley & Sons Canada, Ltd.
Reliable Nutrition Information
in Canada
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Government: Health Canada, Canada Food
Inspection Agency and The Public Health
Agency of Canada
Non Profit Institutions: Dietitians of Canada,
Canadian Medical Association, Heart and Stroke
Foundation and Canadian Cancer Society
Educational Institutions: universities and peerreviewed journals
Copyright 2012, John Wiley & Sons Canada, Ltd.
Reliable Nutrition Information
in Canada
Copyright 2012, John Wiley & Sons Canada, Ltd.
Copyright
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