Download BIOL103 Ch 1 Nutrients for Students F15

Food Choices: Nutrients and
Nourishment
BIOL 103
Chapter 1
What is Nutrition?
• The science of foods (e.g. nutrients and other
substances), including the relationships to health
and disease; processes within the body (ingestion,
digestion, absorption, transport, storage, functions,
and disposal of end products); and the social,
economic, cultural and their components, and
psychological implications of eating.
Factors that Influence Food Choices
1.
2.
3.
4.
5.
Sensory
Cognitive
Genetics
Environmental
Health status
Why do we eat the way we do?
• Sensory
1. Flavor/Taste
2. Texture
3. Appearance
Why do we eat the way we do?
• Cognitive
1. Learned food habits/food
reward
2. Social factors
3. Comfort/discomfort foods
• Behavioral motives
4. Advertising
5. Nutrition and health beliefs
Why do we eat the way we do?
• Environment
1. Economics
1. Lifestyle
1. Availability
1. Cultural Influences
1. Religion
The American Diet
•
•
•
“Meats and potatoes”
Americans age 2 and older
consume, on average, 2157
calories (based on 2000
calories diet)
How healthful is the
“American” diet?
Too little: fruits, dairy, vegetables,
whole grain foods
Too much: saturated fat, sodium,
and sugar
Nutrients
• Definition: Any substance that provides
nourishment essential for growth and the
maintenance of life.
• Essential vs. Non-essential nutrient
– Essential nutrient: ______________________
– Non-essential: _________________________
• How to determine if it is an nutrient?
The six classes of nutrients
(Problem Set#1, Q2)
1. Carbohydrates
2. Proteins
3. Lipids (fat)
4. Vitamins
5. Minerals
6. Water
• Macronutrients vs. Micronutrients
General Functions of Nutrients (what
do they do in our body)
1. Provide ____________
2. Regulate ____________ processes
3. Build ______________ body structures
What does Organic mean?
• Organic or Inorganic?
– What does it mean if
food is organic, in
science?
Carbohydrates
• Carbohydrates: “hydrate
of carbon”
– Made of sugar molecules
• Function:
– ________________ for
cells and tissues
• Dietary sources: starches
and sugars found in
grains, vegetables,
legumes (dry beans and
peas), fruits, dairy
products
Lipids
• Lipids (fats, oils, cholesterol,
phospholipids)
– Made of: ______________
______________________
• Functions:
1. Energy storage as triglycerides
2. Carries fat-soluble vitamins
3. Provides structure for body
cells
• Food sources: fats, oils,
meat, dairy, some plants
(avocado, coconut)
Proteins
• Made of:
____________
• Functions:
1. Energy source
2. Structure for
cells/tissues/body
structures
3. Regulation of body
processes
• Food sources: meats,
dairy products, grains,
legumes, vegetables.
Vitamins
• Made of: carbon, hydrogen,
and any one or combo of
the following (N, O, P, S, or
other elements)
• Functions:
1. helps regulate body
processes
2. help extract energy from
carbs, fat, and proteins
• Food sources: meats,
vegetables, grains, dairy,
fats
Fat vs. Water-Soluble Vitamins
• Fat Soluble Vitamins
– Stored in larger
quantities
• Water Soluble Vitamins
Minerals
• Inorganic substances
• Functions:
1. Structure
2. Regulation
• Food sources: all food
groups
Dietary Minerals
–Macrominerals: Na, Cl, K, Ca, P, Mg
–Microminerals or “trace minerals”: Fe, Zn, Cu,
Mn, Mo, Se, I, Fl
Water
• Most important
nutrient 
• Functions:
1. Temperature control
2. Lubrication of joints
3. Transportation of
nutrients and wastes
• Food sources:
beverages, foods like
fruits and vegetables.
Macronutrients
Macronutrients: From Food to Fuel
Energy in Food
• We eat nutrients so that we can gain energy
– Energy: capacity to do work
– Q: Which nutrients contain sources of potential
energy?
• Kcal vs. Calories
• How do we measure energy in Nutrition?
– Kilocalories (kcal)
• 1000 calories = 1 kilocalorie
• 1 kcal: the amount of energy/heat needed to raise the
temperature of 1 kilogram (kg) of water by 1 degree Celsius.
Energy in Food
Use calorie as a general term for energy and
kilocalorie as a specific measurement or unit of that
energy.
Problem Set #1, Q3
• A) Jeff is eating a snack with 20g of
carbohydrates, 5 grams of proteins, and 3
grams of fat. What is the total amount of
available energy (in kcal) in his snack? (Note:
you will need to show your work for full credit
in an exam).
Problem Set #1, Q3
B) Determine the percentages of kilocalories of
carbohydrate, protein, and fat in Jeff’s snack.
Many of the leading causes of death can be avoided by
good diet and exercise
More than 2/3 of U.S. Adults are
overweight/obese
Diet and Health
• Healthy: “a state of complete physical,
mental, and social well-being AND not
merely the absence of disease or
infirmity.” (WHO)
• Disease
– Acute: ____________________________
• Examples:
– Chronic: __________________________
• Examples:
Diet and Health
• Factors that influence Obesity:
1. Behavior
1. Calorie imbalance
2. Sedentary lifestyle
2. Environment
• Barriers to or opportunities for an active lifestyle
3. Genetics
• Role of heredity
Diet and Health
• Physical Activity
– Role in long-term weight management
• At least ____ mins/day of moderate activity
– Weight-management
• At least ____ mins/day of moderate activity
– What is moderate activity?
Common Study Designs used in
Nutrition Research (PS#1, Q 4 and 5)
1. Cell culture studies: effect of nutrients on cells
1. Animal Studies: effect of nutrients on animals
1. Epidemiological studies: study of disease/death rates
in population groups
1. Case Control Studies: disease vs. those without disease
1. Clinical/Intervention Trials: experimental vs. control
group
– Placebo-controlled
Junk Science
Evaluating Information on the Internet
•
•
•
•
There are no rules for posting on the internet
Consider the source
Keep in mind the scientific method
Be on the lookout for “junk science”
– May distort facts through omission of details