C-1
Food
Choices
and
Human
Health
Introduction
• Food Gives:
– Nutrients
– Calories (kcalories)
• Unit of heat
• Nutrition?
– Study of how nutrients nourish the body
Diet
• Diet?
– Not something you go on and off
– Foods and beverages a person consumes
– Impacts health
• Positively or negatively depending on the diet
Does Diet
Matter?
Does Diet
Matter?
56% of deaths are
nutrition related
(1,2,4,7)
4:10 causes of death
are diet related
Nutrition and Health
• Malnutrition
-Nutrient deficiencies (Undernutrition)
-Nutrient excesses (Overnutrition)
-Both
Lifestyle and Health
• Only thing worse than a bad diet is:
– Excessive alcohol
– Tobacco use
• Kills 443,000 Americans per year (per CDC) (1:5 deaths
in U.S.)
– 7,000 chemicals per puff – rapidly spreads to cause cell damage
in all organs. Some are known carcinogens.
– Makes blood more sticky allowing clots to form
– Narrows blood vessels
• Male smokers lose 13.2 years of life
• Women lose 14.5 years of life
• Cost: $ 75 billion in direct medical costs
$ 82 billion in lost productivity
Total: $157 billion
• We have control!!
Lifestyle and Health
• Chronic disease?
– Take years to develop & causes the body
to break down
• Heart disease
• Diabetes
• Osteoporosis
Risk Factors
• Risk factors
– Increases risk of developing disease
–  # of risk factors =  risk of disease
–  # of risk factors =  risk of disease
Risk Factors
• Non-controllable risk factors include:
– Genetics
– Age
– Gender
– Ethnicity
– Environment
Risk Factors
• Controllable risk factors include:
– Diet
– Alcohol consumption
– Drug use
– Tobacco use
– Stress
– Lack of exercise
– Lack of sleep
– Overweight
– Underweight
Risk Factors
• Snowball of risk factors
– Excess calories 
• Overweight
• High blood pressure
• High cholesterol
 heart disease
Nutrition vs. Genetics in Disease
6 Categories of
6 categoriesNutrients
of nutrients
Energy yielding nutrient?
Nutrient Density
• Nutrient density
– Amount of nutrients per calorie of food
–  nutrients and  calories
– Choose foods based on this
Nutrient Density
• Fruit Juice
– Liquid separated from pulp (fiber)
– Concentrated in calories
– Nutrient dense?
• No! i.e. How many oranges does it take to
make OJ? Get the calories from all oranges.
Nutrient Density
• 100% Juice versus:
– Juice beverages
– Juice drinks
– Juice Cocktails
– All are glorified Kool-Aid; mostly sugar
Nutrients in Food
• Essential nutrients
– Nutrients body needs,
but can’t make
-Must eat
Nutrient
Class
Essential
nutrient
Carbohydrate
Glucose
Fat
Linoleic acid
linolenic acid
Protein
9 amino
acids of 20
Vitamins
All 13
Minerals
25
Water
Yes
Terms
Nonnutrients
• Phytochemicals
– Non-nutrient
– Plant foods
– May reduce disease
– Give color, taste, etc. to foods
• Blueberries, tomatoes
What is a Healthy Diet?
What is a Healthy Diet?
• Adequacy
– Eat enough of all essential nutrients
What is a Healthy Diet?
• Balance
– Eat enough, but not too much of any food
or nutrient
What is a Healthy Diet?
• Calorie control
– Don’t eat excess calories
What is a Healthy Diet?
• Moderation
– Eat nothing in excess
What is a Healthy Diet?
• Variety
– Eat different foods from all food groups
Why Do We Eat?
Why Do We Eat?
• Factors that drive food choices
•Advertising
•Availability
•Economy
•Emotional comfort
•Habit
•Personal preference
•Positive associations
•Region of the country
•Social pressure
•Values or beliefs
•Weight
•Nutritional value
The Stages of Behavior Change
Science of Nutrition
• Young science (~1900)
• Information learned by experiments
• Knowledge base changes
OBSERVATION & QUESTION
Identify a problem to be
solved or ask a specific
question to be answered.
HYPOTHESIS & PREDICTION
Formulate a hypothesis—a
tentative solution to the problem
or answer to the question—and
make a prediction that can
be tested.
EXPERIMENT
Design a study and
conduct the research to
collect relevant data.
RESULTS & INTERPRETATIONS
Summarize, analyze, and
interpret the data; draw
conclusions.
HYPOTHESIS
SUPPORTED
THEORY
Develop a theory that
integrates conclusions
with those from
numerous other studies.
HYPOTHESIS NOT SUPPORTED
NEW OBSERVATIONS
& QUESTIONS
Fig. 1-3, p. 13
Research Designs
• Epidemiological Study
– Whole populations
– Tells correlations between diet & health
– Identifies possible disease causes
Research Designs
• Case Study
– Study of individuals
– Observe treatment and effects
– Leads to more research ideas
Research Designs
• Laboratory Study
– Controlled conditions
– Tests disease causes and treatments
Research Designs
• Intervention Study
– Intervene in people’s diets
– Experimental group
– Control group
– Blind study
– Double blind study
– Shows impact of treatment
Science of Nutrition
• One study result doesn’t = a fact
– Preliminary finding
– May be discredited later
– Do not change diet!
– Repeat findings are most reliable
• Findings proven enough times are
accepted as fact
• Being published does NOT = fact
Evaluating Nutrition Info
Evaluating Nutrition Info
Evaluating Nutrition Info
• Consider the following:
– Published in a peer-reviewed journal
Evaluating Nutrition Info
• Similarity between controls
• Sample size
• Placebo effectively administered
• Blind or double blind
• Findings put into proper context
• Consider funding source
Evaluating Nutrition Info
• Confounding factors
– Diet, exercise, tobacco use, alcohol
consumption, drug use, lifestyle…
• Consider applicability to you
• Does it make sense!
Media and Nutrition
• Report preliminary findings
• Don’t understand science
• Sensationalizes things that are true
– Even if something is true, consider the big
picture and overall diet
Controversy 1
• Nutrition quackery
– Claim for a miracle cure without scientific
evidence to back it up
• Weight loss, body building, energy pills…
• Will never go away
-$27 billion dollars per year
ABC video clip:
“Weight Loss Ads”
Weight Loss Ads
Click on the
gfffgsd
man and then
Click
the man and on each item
eachon
item
Reliable Nutrition Advice?
• Grandma?
• Health food store clerk?
• Coaches?
• Personal trainer?
• Physicians?
Reliable Nutrition Advice
• Nutritionist
– No legal definition
• Registered Dietitian
– Accredited school
– BS
– Internship
– National Exam
• Continuing professional education
• Careers in Dietetics
– Academy of Nutrition and Dietetics (ADA)
Association of Nutrition Experts – Professional Member
Internet
Research
Questions