Chapter 1
Nutrition: Food for Health
© 2008 Thomson - Wadsworth
How Healthy is the Typical
American Diet?
50% of the population does not
consume sufficient amounts of foods
that provide necessary nutrients.
Diet and Health
• Chronic Diseases
Four of ten leading causes of death
have a relationship with diet (heart
disease, cancer, strokes, diabetes)
Many leading causes of death have a
relationship with obesity.
Poor dietary habits are considered a
risk factor for many diseases
Food Choices
• Personal preferences for flavors
• Habits are comforting and food choices
are often just a habit.
• Ethnic heritage or traditions are strong
influences on eating.
• Social interactions such as special events,
customs, and holidays
Food Accessibility
• Transportation and mobility
• Available income
• Food storage and preparation
equipment
• Convenience
Cultural and Personal
Background
• Religious dietary laws
• Ethnic menu preferences
• Social acceptability, values such as
political views, or environmental concerns
may affect food choices
• Psychological and emotional factors, eating
for comfort
• Health concerns
• Body weight and image can affect food
choices
Nutrition Terms
Nutrition is a
science that studies
the interactions
between living
organisms and
food.
What Are Nutrients?
Nutrients: the chemicals in foods that
provide energy and structure, and help
to regulate body processes. They are
critical to human growth and function.
1. carbohydrates
2. fats and oils
3. proteins
4. vitamins
5. minerals
6. water
The Nutrients
Essential nutrients are those the
body cannot make or cannot make in
sufficient quantities to meet needs.
These are also called indispensable
nutrients.
What Are Nutrients?
• Macronutrients: nutrients required in
relatively large amounts.
– Provide energy to our bodies
– Carbohydrates, fats and oils, proteins
• Micronutrients: nutrients required in
smaller amounts.
– Vitamins and minerals
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.
The Nutrients
Chemical composition of nutrients includes
both organic (those that contain carbon
bonded to hydrogen) and inorganic (those
that do not contain carbon bonded to
hydrogen) compounds.
• Carbohydrate, protein, and fat/lipids are organic.
Vitamins are organic, essential nutrients that allow
the body to obtain energy from carbohydrate, fat,
and protein.
• Minerals and water are inorganic, essential nutrients
that are found in the bones, teeth, and body fluids.
Energy From Nutrients
• We measure energy in kilocalories (kcal).
• Kilocalorie: amount of energy required to
raise the temperature of 1kg of water by 1oC.
• On food labels, “Calorie” with capital “C”
actually refers to kilocalories. (technically
1 kcal=1000 calories or 1 Calorie)
• 100 Calories = 100 kcal
• Internationally, food energy is measured in
kilojoules. (1 kilocalorie = 4.18 kilojoules)
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 a
systematic, unbiased approach to
examine the interaction of food,
nutrients and health.
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.
What Makes a Good Experiment?
A well-conducted experiment requires:
Quantifiable Data
- Can we measure the information in a
scientific manner?
- Can we ensure that the population ate or
drank what we said they did?
Appropriate Experimental Population
- Is the population large enough and
pertinent to the study?
What Makes a Good Experiment?
• Control groups act as a standard of
comparison.
• Placebos are identical in appearance to the
actual treatment but 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
• Sample sizes must be large to accurately
detect differences.
The Science of Nutrition
• Publishing Research
 A peer review process is used to evaluate the
procedures used and the conclusions drawn from a
study.
 Look at the source of the information
 When a study has validity it means that the
conclusions were supported by the findings.
 Replication is used to confirm or disprove findings.
• Research results, who to believe?
 Be careful interpreting news reports
 Beware of testimonials and claims, or one study sited
 Who funded the study? Are they selling a product?!!
Finding Reliable Nutrition Info
• Websites sponsored by official govt
agency, university, college, or
hospital/medical center: .gov,.edu,.org
• Search for well established,
professional peer-reviewed journals.
Professional Organizations that Provide
Reliable Nutrition Information:
• Academy of Nutrition and Dietetics -formerly
American Dietetic Association (ADA)
• American Society for Clinical Nutrition
(ASCN)
• Society for Nutrition Education (SNE)
• American College of Sports Medicine
(ACSM)
Nutrition Information &
Misinformation
• Red Flags of Nutritional Quackery
 Nutritional misinformation can be identified
by using the following eight red flags:
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Selling a product, book, etc.
Satisfaction guaranteed
Quick and easy fixes
“Natural”
One product does all
Paranoid accusations
Personal testimonials
Meaningless medical jargon
Who are the Nutrition Experts?
 Registered Dietitians (RD’s)
Must complete academic coursework and an
internship/work experience, pass a national exam
Must continue with education to maintain registration
 Certified Nutritionist (CN)
May be required to be licensed in some states, WA
state uses Certified Nutritionist or CN
Dietitians may be called nutritionists, but not all
nutritionists are dietitians
Watch out for “Nutritionist” and MD’s!