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Week 1

Lecture | Study Guide | Major Assignment

The Science of Nutrition- Chapter 1

Any questions asked in the following lecture are for your reflection; the answers to these questions will not be turned in to me.

I encourage you to look over the chapter before you start reading it. Get an overview of what's to come. Read the 'Student Learning Outcomes'; read the information in the margins; look at the Tables; test yourself with the 'Knowledge Check'; complete the 'Take Action', 'Case Study' , and 'Critical Thinking' sections; read the 'Summary'; complete the 'Study Questions'. There's a lot of information and useful study tips packed into each chapter.

Chapter One gives an introduction to the study of nutrition.

In A Nutshell:

	Nutrition is the study of the food substances vital for health and the study of how the body uses these substances to promote and support growth, maintenance, and reproduction of cells. Research in the field has been especially vigorous from the past century to the present times.
	Nutrients in foods fall into 6 classes: carbohydrates, lipids (mostly fats and oils), proteins, vitamins, minerals, and water. The first 3, along with alcohol, provide energy for the body to use.
	The body transforms the energy contained in carbohydrates, protein, and fat into other forms of energy, which allow the body to function. Fat provides, on average, 9 kcal/g, whereas protein and carbohydrate each provides, on average, 4 kcal/g. Vitamins, minerals, and water do not supply energy to the body but are essential for proper body function.
	A basic plan for health promotion and disease prevention includes eating a varied diet, performing regular physical activity, not smoking, not abusing nutrient supplements (if used), getting adequate fluid and sleep, limiting alcohol intake (if consumed), and limiting or coping with stress.
	The focus of nutrition planning should be on food, not primarily on dietary supplements. The focus on foods to supply nutrient needs avoids the possibility of severe nutrient imbalances.
	Results from large nutrition surveys in the United States such as CSFII and NHANES suggest that some of us need to concentrate on consuming foods that supply more vitamin A, certain B vitamins, calcium, iron, zinc, and dietary fiber.
	There are no true "junk" or "bad" foods. The focus should be on balancing a total diet by choosing many nutritious foods.
	The scientific method is the procedure for testing the validity of possible explanations of a phenomenon, called hypotheses. Experiments are conducted to either support or refute a specific hypothesis. Once we have much experimental information that supports a specific hypothesis, it then can be called a theory. All of us need to be skeptical of new ideas in the nutrition field, waiting until many lines of experimental evidence support a concept before adopting any suggested dietary practice.
	Evaluation of nutritional state involves analyzing background factors, as well as anthropometric, biochemical, clinical, dietary, and economic assessments. It is not always possible to detect nutritional inadequacies via nutrition assessment since signs and symptoms of deficiencies are often nonspecific and may not appear for many years.

Food Choices
Reasons given for people making the food choices they do:

	personal preference
	habit
	ethnic heritage or tradition
	social interactions
	availability, convenience, cost
	positive and negative associations
	emotional comfort
	values
	body weight and image
	health benefit

The Nutrients:

What are nutrients?
What are essential nutrients?

	There are 6 classes of nutrients: carbohydrates, proteins, lipids (fats), vitamins, minerals, and water.
	In Table 1-1, you can see that these nutrients are divided into Energy-yielding and Non-Energy yielding nutrients.

Which nutrients provide energy? which promote growth & development? which regulate body processes?

	Carbohydrates (CHO), proteins, and fat are energy-yielding nutrients.
	Energy is defined as the ability to do work.
	Energy is measured in units called calories. (Notice: lower case "c")
	One calorie is the amount of heat needed to raise the temperature of 1 gram of water 1 degree C. (A gram is the ~ weight of a large paper clip or the weight of 1/2 teaspoon of salt).
	The energy/heat in food is measured in kilocalories (abbreviated kcal or kcalories).
	1000 calories = 1 kilocalorie
	1 kcal is the amount of heat needed to raise the temperature of 1000 grams of water 1 degree C. ( 1000 grams is equivalent to 1 kilogram is equivalent to 1 liter)
	In the United States, labels use Calorie (with a capital "C") to mean kcal.
	How many pennies make-up a ten dollar bill? Right! 1000.
	A calorie is like one penny; a kcal is like a ten dollar bill.
	A food label listing 1 cup of whole milk with 150,000 calories is crazy, when it could list it as 150 kcal or 150 Calories.
	Are you still with me?
	Appendix H, pg.A-82 - English-Metric Conversions & Nutrition Calculations can be useful.
	Carbohydrate (CHO = abbreviation for Carbohydrate; Why? carbohydrates contain carbon, hydrogen, and oxygen- CHO), proteins, and fat are energy-yielding nutrients.
	According to Table 1-2, CHOs yield 4 kcal/g; fat yields 9 kcal/g; and protein yields 4 kcal/g.
	Alcohol is not a nutrient, but it too yields kcals.
	1 g alcohol = 7 kcal. Is it any wonder we gain excess body weight if we consume too much alcohol?
	See Appendix H, pg. A-84, Example 3: Calculating % of Calories Supplied . . .

I'm holding an imaginary cookie. It contains 10 grams of CHO, 10 grams of Protein, and 10 grams of fat. How many kcals total does it contain?

4(10 g CHO) = 40 kcal
4(10 g PRO) = 40 kcal
9(10 g Fat) = 90 kcal
170 kcal

What percentage of this cookie comes from fat?

90 kcal from fat X 100 = 52.9%
170 kcal total

What percentage of this cookie comes from CHO?

40 kcal from CHO X 100 = 23.5%
170 kcal total

What percentage of this cookie comes from PRO?

If you total the percentages, they should equal ~ 100% which represents the entire cookie. Normally, you would round-up the percentages to 53%, 24%, etc.

Make sure you can do calculations like this the old-fashioned way.
During the midterm and final exams, you will not be permitted to use a calculator.

Go to the kitchen; get a food package that has the Nutrition Facts label. Multiply the grams of CHO, PRO, and fat by the number of kcals they yield. Do you come up with the same total number of kcals as the manufacturer? The FDA says it's okay for the numbers to differ by ~ ± 10%.

Vitamins and Minerals do not provide energy.
They help to release energy/heat from CHOs, Proteins, and fat.

Water does not provide energy either. It participates in metabolic reactions and transports materials in the body. It too is absolutely vital to life.

The Science of Nutrition
The information imparted in this textbook is based on nutrition findings garnered from scientific studies. Science is never "finished". The findings from scientific studies are like pieces of a puzzle, like clues used to solve a mystery. The beauty of this is that our knowledge of nutrition is constantly growing and changing as new scientific findings come in. Think of scientific results as "findings" not "facts" since these findings are subject to change over time.

Define the term "nutrition".

Nutrition Research is based on the scientific method:
1. Making observations that others can repeat and confirm.
2. Developing an hypotheses.
3. Conducting tests/experiments to support/refute the hypotheses.

Experiments are conducted to test the validity of an hypotheses.

Explain how the scientific method is used in developing hypotheses and theories in the field of nutrition.

Nutrition Assessment
This is an evaluation of a person's nutrition status using health, socioeconomic, drug, & diet histories; anthropometric measurements; physical exams; and laboratory tests.

Historical information- What's the significance of knowing this information?

Anthropometric data-measures (such as height and weight) taken from a person's body. This information is then compared to established standards.

Physical Exam
See Table 16-6 "Physical Signs of Malnutrition in Children" on pg. 563 in your text.

Laboratory tests-blood or urine samples are analyzed by a lab and the results compared with standard values.

Discuss the limitations of nutritional assessment.

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Diet and Health
See Figure 1-1 on pg.4 " Leading Causes of Death in the United States" .

Identify diet and lifestyle factors that contribute to the leading causes of death in North America.

What is a 'risk factor'?
Which risk factors pertain to you?

Describe the role of genetics in the development of nutrition-related diseases.

Study Guide   Chapter 1

This Study Guide is for your use only. You will not turn this in to me.

1. What are the various factors that affect our food choices?

2. What are the six classes of nutrients? Define the terms inorganic and organic.
    What makes a nutrient "essential"? What are the energy-yielding nutrients? Which
    nutrients do not yield energy when broken down? How many kcals are in each
    energy-yielding nutrient? Define kcal, phytochemical, zoochemicals

3. How do vitamins differ from the energy-yielding nutrients? How do minerals differ from
    the energy-yielding nutrients? What is the function of water in the body?

4. Define the "science of nutrition". What four questions should people ask before
    concluding that an experiment has shown that a nutrient cures a disease or alleviates
    a symptom?

5. What information is provided by the following nutrient assessment methods: historical
    information, anthropometric data, physical examinations, lab tests, and population
    surveys? What is the goal of Healthy People 2010?

6. What is the relation between risk factors and disease? Define risk factor. List the ten
    leading causes of death in the United States.

7. Identity reliable sources of nutrition information.

Becky Alejandre, Professor - Nutrition	Instructor's contact information Email: alejanb@arc.losrios.edu Phone: (916) 484-8145 FAX: (916) 484-8030	ARC Homepage	ARC Library
Office Location: Room #762 Health & Education Division (located between the tennis courts and the gym)		Office Hours: Mon. 8:00-10:00 a.m. Tues. 10:30-11:30 a.m. Wed. 10:30-11:30 a.m. (online) Thurs.10:30-11:30 a.m. Fri. 7:00-8:00 a.m. (online)

Becky Alejandre, Professor - Nutrition

Becky Alejandre,
Professor - Nutrition