Transcript ppt

What is Nutrition?
•The science of food, the nutrients and the
substances therein,
•their action, interaction, and balance in
relation to health and disease,
•and the process by which the organism
ingests, digests, absorbs, transports, utilizes,
and excretes food substances.
States of Nutritional Health
Desirable Nutrition
nutrients consumed support body functions and stores for times of
increased need.
Malnutrition
–Undernutrition
nutrient intake does not meet minimal needs; can lead to reduced
biochemical function and serious long term effects
–Overnutrition*
nutrients are consumed in excess of the body needs; can lead to toxicity or
obesity
* biggest problem in the US due to excess of saturated fats and salt
high in fiber
and fluid
high in fruit
low in saturated
and trans fats
*
high in
whole grains
little or no
alcohol
high in
vegetables
adequate in
nutrients
moderate
in calories
Nutrition
and your
Health
Leading Cause
of Death in the
U.S.
•4 of top 6 are
nutrition-dependent
Nutrition and Your Health
Poor diet is a risk factor for several chronic diseases and ailments
–heart disease
–cancer (e.g., colon, breast)
–diabetes
–stroke
–hypertension
–Anemia (iron-deficiency)
–osteoporosis
–cirrhosis of the liver
–fetal alcohol syndrome
–stunted growth
Poor diets kill 300,000 people/year from these top 3 diseases alone
The Science of Nutrition
•Nutrition is true science but a young science
–1897 – first vitamin identified
–1940’s – first protein structure
•It is a complex, interactive science
•Research Design can take many forms:
–Epidemiological study
–Case study
–Laboratory study
–Intervention study
Pellegra
Scientific Method
Nutrition, Disease, and Genetics
New Research Fields:
•nutritional genomics
•molecular nutrition
•nutrigenomics
Agouti Mice
How Aware are You of your
Nutritional Health?
•overall population is getting fatter
•probably due to an increasingly sedentary lifestyle,
•poorer diets,
•and a busier work schedule
World Malnutrition
• Undernutrition: ~800 million people
• Nutrient Deficiency: 2-3.5 billion people
• Overnutrition: ~ 1.1 billion
Undernutrition
Undernourished Population: 2002-2004
From United Nations (2004)
USA Overnutrition numbers
• 2000:
– 64% of people are considered overweight
– 30% of people are considered to be obese
– 1/7 children and teenagers are considered to be
overweight
Obesity Rates across the US
Key:
No data available
1991
<10%
10% to 14%
15% to 19%
20% to 24%
≥ 25%
In 1991, only 4 states had
obesity rates >15 percent.
2002
In 2002, 29 states had obesity rates of 20 to 24
9-1, p. 312
percent and rates of 3 more topped Fig.
25 percent.
Obesity Rates
http://www.cdc.gov/obesity/data/trends.html
Obesity across the World
More people in the developing world are now overweight than hungry
The Problem with Globalization
• Globalization: as the middle class of a third world or developing
country expands the opportunity to purchase a wider range of products
increases:
– Grocery stores
– Electronic goods
– Automobiles
• Globalization increases the availability of unhealthy food sources
– Sweetened beverages
– Vegetable oils
– Animal source foods
• Globalization increases sedentary behavior
– Increase television viewing
– Decrease physical exercise
The Changes in Mexico
• 1989:
– <10% of the population is considered to be overweight
– Obesity/Type II Diabetes were not health issues
– Hunger and poverty were the main issues of concern
• 2006:
– 77% of males are considered to be overweight or obese
– 66% of females are considered to be overweight or
obese
– 1/7 have Type II Diabetes and it is spreading
The Problem
with Eating
Away from
Home
Super-Size Me?
More Calories are Available
More Caloric Sweeteners are Available
More Sugary Soft Drinks are Available
Why Should You Eat?
We eat to get Nutrients.
Nutrients are the nourishing substances we must
obtain from food. These essential substances are vital
for growth and maintenance from infancy to
adulthood.
The minimum diet for healthy growth, development,
and maintenance MUST contain about 45 essential
nutrients.
Function of Nutrients
•Energy Providers
•Growth and Development Providers
•Body Processes Regulators
Energy Providing Nutrients
Food Energy is measured in calories (kilocalorie, Calorie):
The amount of heat energy necessary to raise the temperature of a liter
(1 kilogram) of water 1 degree Celsius.
Metabolic Rate (MR): The overall rate at which nutrients are broken
down to produce energy for ATP and heat
Basal Metabolic Rate (bMR): The rate at which a quiet, resting,
fasting body breaks down nutrients to liberate energy. The thyroid hormone
is the main regulator of bMR
•Energy Producing
Nutrients:
•Carbohydrates
•Fats/Lipids
•Proteins
Table 1-3, p. 6
Growth and Development Nutrients
Body Process Regulator Nutrients
•Vitamins
•Minerals
•Water
•Proteins (some functions)
•Fiber (from carbohydrates)
Why Do We Eat What We Do?
Body Image
Nutritious Diet Characteristics
•Adequacy
–Foods provide enough of each essential nutrient, fiber, and energy
•Balance
–All food groups are represented; one is not overrepresented
•Calorie Control
–Food provides enough energy to maintain weight
•Moderation
–There is no excess nor unwanted food groups
•Variety
–Foods differ from one day to the next
Dietary Reference Intakes (DRI)
Represent up-to-date optimal, and safe nutrient intakes
for healthy people in the US and Canada
They are based on scientific investigation
DRI Committee Goals are to:
1. Set Recommended Intake Values (RDA, AI)
2. Facilitate Nutrition Research and Policy (EAR)
3. Establish Safety Guidelines (UL)
4. Prevent Chronic Diseases (AMDR)
Nutrient Standards
Daily Values
Standards used only on food
labels to enable customers to
compare the nutrient values
among foods
They reflect the needs of an
average person – someone
eating 2000-2500
calories/day
Are much less useful as
nutrient intake goals for
individuals
1992 Nutritional Requirements
The New 2005 MyPyramid
Process to replace the 1992 model was secret
No more food hierarchies
According to USDA staff:
Influence of food lobbies is
•Keep physically active
apparent
•Eat in moderation
•Make personalized food choices
•Eat a variety of foods in the recommended number of servings
•Pursue gradual dietary improvement
What’s Your Excuse?
Most Often
Knowledge
is Key
2005 US Dietary Guidelines
Fig. 1-5a, p. 16
2005 US Dietary Guidelines
Fig. 1-5b, p. 16
2005 US Dietary Guidelines
Fig. 1-5c, p. 16
2005 US Dietary Guidelines
Fig. 1-5d, p. 16
2005 US Dietary Guidelines
Fig. 1-5e, p. 16
2005 US Dietary Guidelines
Fig. 1-5f, p. 16
2005 US Dietary Guidelines
Fig. 1-5g, p. 16
2005 US Dietary Guidelines
Fig. 1-5h, p. 16
U.S.
Nutrition
Objectives
2010