Transcript whatisnutrition

Chapter 1
Nutrition: Food for Health
Nutrition Terms
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Nutrition is a science that studies the
interactions between living organisms and
food.
Food provides nutrients and energy.
Nutrients are chemical substances in
foods that provide energy and structure
and help regulate body processes.
How Healthy is the Typical
American Diet?
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Processed and convenience foods are easily
obtainable but may not provide necessary
nutrients.
Processed and convenience foods contain
elevated levels of calories, sodium and fat.
We don’t eat enough whole grains,
vegetables, fruits, seafood, or dairy
products.
Nutrition-Related Deaths
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Nutrition Terms
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Essential Nutrients must be provided in the
diet.
Fortified foods have nutrients added.
Enriched grains have thiamin, riboflavin,
niacin, iron and folic acid added.
Dietary Supplements contains one or more of
the following: vitamins, minerals, plantderived substances, amino acids, or
concentrates or extracts.
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.
Classes of Nutrients: Macronutrients
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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.
Classes of Nutrients: Macronutrients
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Carbohydrates
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Classes of Nutrients: Macronutrients
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Lipids
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Classes of Nutrients: Macronutrients
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Proteins
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Macronutrient: Carbohydrates
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Carbohydrates include sugars and starches.
Carbohydrates provide 4 kilocalories/gram.
Fiber belongs to the category of
carbohydrates but does not provide energy.
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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
abundantly in the body.
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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 to prevent certain diseases.
Lipids contain 9 kilocalories/gram.
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.
Categories of Macronutrients: Proteins
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Proteins are made up of different
combinations of amino acids.
Proteins provide 4 kilocalories/gram.
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.
Micronutrients can be found in most fresh
foods.
Classes of Nutrients: Water
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Water is a macronutrient, meaning that it is
required in large amounts.
Water does not provide kilocalories.
Water makes up approximately 60% of the
healthy human body.
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.
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.
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.
Malnutrition
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Overnutrition
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Diet, Genes and Health
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Nutrigenomics The study of how diet affects
genes and how genetic variation can affect
the impact of nutrients on health.
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Food Availability
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Geography
Transportation and mobility
Available income
Food storage and preparation equipment
Cultural and Personal Background
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Religious dietary laws
Ethnic menu preferences
Social acceptability
Personal preference
Psychological and emotional factors
Health concerns
FIGURE 7 - The food system
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Definition of Adequate Diet
Several major conditions define an adequate diet, necessary for an individual to
stay active and healthy:
· It should provide adequate energy and protein.
· It should provide micronutrients (vitamins and minerals) in sufficient quantities to
maintain good health
· It should be safe and free from contaminants, parasites and toxins which may be
injurious to health.
· It should be culturally acceptable and, in addition, should satisfy the palate and
be capable of providing pleasure to the consumer.
Nutrient Density
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Nutrient density is a measure of the nutrient a
food provides compared to its energy
content.
Copyright © 2013 John Wiley & Sons, Inc. All rights reserved.
Copyright © 2013 John Wiley & Sons, Inc. All rights reserved.
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.
Balance Your Choices
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There is no good food/bad food.
Balancing foods allow all foods to fit in a
healthy diet.
Balance calories in with calories out.
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.
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?
What’s the source?
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Is it selling something?
Is it someone’s opinion?
Who is a legitimate source of information?
Who will benefit when you purchase this product?
Identifying Reliable Nutrition
Information
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Is it based on good science?
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Is the information based on well-designed,
accurately-interpreted research studies?
Has this product stood the test of time?
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Many studies duplicated over a period of time
show the same results