Chapter 1 NUTRITION: 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 Copyright 2012, John Wiley & Sons Canada, Ltd.

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. Copyright 2012, John Wiley & Sons Canada, Ltd.

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. Copyright 2012, John Wiley & Sons Canada, Ltd.

Nutrition-Related Deaths

Copyright 2012, John Wiley & Sons Canada, Ltd. 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.

Copyright 2012, John Wiley & Sons Canada, Ltd. Classes of Nutrients: Macronutrients

Copyright 2012, John Wiley & Sons Canada, Ltd. 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.

Copyright 2012, John Wiley & Sons Canada, Ltd. 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.

Copyright 2012, John Wiley & Sons Canada, Ltd. Carbohydrates, Lipids and Proteins

Copyright 2012, John Wiley & Sons Canada, Ltd. 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.

Copyright 2012, John Wiley & Sons Canada, Ltd. 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.

Copyright 2012, John Wiley & Sons Canada, Ltd. 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.

Copyright 2012, John Wiley & Sons Canada, Ltd. Categories of Macronutrients: Proteins 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 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. Copyright 2012, John Wiley & Sons Canada, Ltd.

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 Copyright 2012, John Wiley & Sons Canada, Ltd.

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. Copyright 2012, John Wiley & Sons Canada, Ltd.

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. Copyright 2012, John Wiley & Sons Canada, Ltd.

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. Copyright 2012, John Wiley & Sons Canada, Ltd.

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. Copyright 2012, John Wiley & Sons Canada, Ltd.

Food Availability Food availability depends on: Geography Transportation and mobility Available income Food storage and preparation equipment Copyright 2012, John Wiley & Sons Canada, Ltd.

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 Cultural and Personal Background Copyright 2012, John Wiley & Sons Canada, Ltd.

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. Copyright 2012, John Wiley & Sons Canada, Ltd.

Nutrient Density Copyright 2012, John Wiley & Sons Canada, Ltd.

Choosing a Healthy Diet Copyright 2012, John Wiley & Sons Canada, Ltd.

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. Copyright 2012, John Wiley & Sons Canada, Ltd.

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. Copyright 2012, John Wiley & Sons Canada, Ltd.

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. Copyright 2012, John Wiley & Sons Canada, Ltd.

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 Copyright 2012, John Wiley & Sons Canada, Ltd.

The Scientific Method Copyright 2012, John Wiley & Sons Canada, Ltd.

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? Copyright 2012, John Wiley & Sons Canada, Ltd.

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. Copyright 2012, John Wiley & Sons Canada, Ltd.

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. Copyright 2012, John Wiley & Sons Canada, Ltd.

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. Copyright 2012, John Wiley & Sons Canada, Ltd.

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? Copyright 2012, John Wiley & Sons Canada, Ltd.

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 Copyright 2012, John Wiley & Sons Canada, Ltd.

Reliable Nutrition Information in Canada Copyright 2012, John Wiley & Sons Canada, Ltd.

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