Transcript 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.
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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
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“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
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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