chapter 1 nutrition: food for health. nutrition terms nutrition is a science that studies the...

Chapter 1NUTRITION:Food for Health

Nutrition Terms Nutrition is a science that studies the

interactions between living organisms and the food they consume.

Nutrients and energy are provided by food.

Energy is measured in kilocalories.

Essential nutrients must be supplied in the diet.

Copyright 2012, John Wiley & Sons Canada, Ltd.

The Canadian Diet

Past 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

Present 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


The Canadian Diet

Concern in the past was obtaining all the nutrients needed for good health.

Concern now is limiting consumption to prevent obesity and chronic diseases associated with it.



How Healthy is the Typical Canadian Diet? 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.

How Healthy is the Canadian Diet? (continued) 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.



Nutrition-Related Deaths


Classes of Nutrients: Macronutrients 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


Classes of Nutrients: Macronutrients 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

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.


Carbohydrates, Lipids and Proteins


Classes of Macronutrients: Lipids

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.


Classes of Macronutrients: Lipids

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.


Categories of Macronutrients: Proteins

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

Proteins are made up of different combinations of amino acids.

Proteins provide 4 kcalories/gram.


Classes of Nutrients: Micronutrients

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 (continued)

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.



Classes of Nutrients: Water

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.

Composition of the Human Body


Functions of Nutrients: Providing Energy 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 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

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.


Nutrient Intake and Health

Malnutrition can mean eating too little or too much of one or more nutrients.

Undernutrition is malnutrition caused by eating insufficient amounts of energy-providing foods.

Overnutrition is malnutrition caused by eating an excess of energy-providing foods.


Food Availability

Food availability depends on:GeographyTransportation and mobilityAvailable incomeFood storage and preparation equipment


Health is impacted by cultural and personal variables such as:Religious dietary lawsEthnic menu preferencesSocial acceptabilityPersonal preferencePsychological and emotional factorsHealth concerns

Cultural and Personal Background


Nutrient Density

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.


Nutrient Density


Choosing a Healthy Diet


Eat a Variety of Foods

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.


Everything in Moderation

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.


Understanding Science 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.


The Scientific Method 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: Observation Hypothesis Theory


The Scientific Method


What Makes a Good Experiment?A well-conducted experiment requires:

Quantifiable Data Can we measure the information in a scientific manner?

Appropriate Experimental Population Is the population large enough and pertinent to the study?

Proper Controls Can we ensure that the population ate or drank what we

said they did?


What Makes a Good Experiment? 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.


Types of Nutrition Research Studies 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.


Identifying Reliable Nutrition Information

Does the information make sense? For example, can you really lose forty pounds in

one week? Where did the information come from?

Information from personal testimony or from one health care professional is probably not reliable.


Identifying Reliable Nutrition Information

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?


Reliable Nutrition Information in Canada 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 peer-reviewed journals


Reliable Nutrition Information in Canada


Copyright

Copyright © 2012 John Wiley & Sons Canada, Ltd.

All rights reserved. Reproduction or translation of this work beyond that permitted by Access Copyright (The Canadian Copyright Licensing Agency) is unlawful. Requests for further information should be addressed to the Permissions Department, John Wiley & Sons Canada, Ltd. The purchaser may make back-up copies for his or her own use only and not for distribution or resale. The author and the publisher assume no responsibility for errors, omissions, or damages caused by the use of these programs or from the use of the information contained herein.

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chapter 1 nutrition: food for health. nutrition terms nutrition is a science that studies the...

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