Food, Nutrition, and Health

download report

Transcript Food, Nutrition, and Health

Chapter 1
Basic definitions:




Nutrition-deals with the food
people eat and how their
body use it
Dietetics – health profession
responsible for applying
nutritional science to
promote human health and
treat disease.
Registered dietician – the
nutrition authority on the
health care team.
Public health nutritionistnutrition authority in the
community
The most recent report
published by the U.S. Dept. of
Health and Human Services in
this series, Healthy People
2010 focuses on the nation’s
main objective of positive
health promotion and disease
prevention.
The three public health goals
are:
 1. An increase in the span of
healthy life.
 2. Reduction of health
disparities.

3. Access to preventive
health care services.

Preventive-identifies
risk factors that
increase a person’s
chances of
developing a
particular health
problem.

Traditional-only
attempts changes
when symptoms of
illness or disease
already exist
Nutrients in food must
perform the following
three basic functions.

1. Provide energy

2. Build tissue

3. Regulate metabolic
processes
Metabolism: the sum
of all body processes
that accomplish these
three basic lifesustaining tasks.
Energy Sources:
 Carbohydrates:
provide the body’s primary
source of fuel for heat and
energy
maintain the body’s
back-up store of quick
energy as glycogen, which
is sometimes called
“animal starch”
Kilocalories-human energy
measured in heat units.
Each gram of
carbohydrate consumed
yields 4 kcal/gram of
body energy.


This number is called
the “fuel factor” for
carbohydrates.
In a well-balanced
diet, carbohydrates
should provide about
45%-65% of the total
kcalories.
Example: If a sandwich
contains 60 g of
carbohydrates, how
many kcalories does it
provide?
 Answer: 60 g X 4 kcal
= 240 kcalories.
Fats provide the body’s secondary
storage of heat and energy.

Example: What is the number of calories
from fat in a hamburger that contains
30 grams of fat?
This form is more concentrated.




Fat yields 9 kcal/gram for each gram
consumed.
Fat has a “fuel factor” of 9.
In a well-balanced diet fats should
provide no more than 20% - 35% of
total kcalories.
In a diet that is 1,800 kcal/day, what
is the approximate number of
kiloalories per day from fat?
Answer: 360-630 kilocalories
Answer: 30 g X 9 kcal = 270
kcalories.
The primary function of
protein is tissue building
and repair, but some of it
may be used for energy if
necessary.

Protein yields 4
cal/gram.

Protein has a “fuel
factor” of 4.

In a well-balanced diet
protein should provide
about 10% to 35% of
total kcalories.
Example: What is the
number of kilocalories
from protein in a steak
that contains 60 grams
of protein?

Answer: 60 g X 4 kcal
= 240 kcalories.
Proteins- primary
function is tissue
building.

Dietary protein
provides amino
acids which are the
building units
necessary for
constructing and
repairing body
tissues.
An example:
Vitamin C is used to
help tissue building
Fatty acids- help build
the central fat
substance of cell walls
and promote
transport of fatsoluble materials
across the cell wall.
Vitamins and minerals are
nutrients that help regulate
many body process.

Many vitamins function
as coenzyme factors,
which are components of
cell enzymes, in
governing chemical
reactions during cell
metabolism
Other nutrients:
Water and fiber also
function as regulatory
agents.


Water is the
fundamental agent for
life itself, providing the
essential base for all
metabolic processes.
Fiber provides the bulk
to help regulate the
passage of food material
thru the GI tract.
Optimal nutrition means
that a person receives and
uses substances that are
obtained from a varied
diet.
Undernutrition-Dietary
surveys have shown that
approx. 1/3 of the U.S.
population lives on
suboptimal diets.


It does not mean that
these Americans are
undernourished.
On average someone
receiving less than the
desired amounts of
nutrients has greater risk
for physical illness than
someone receiving the
appropriate amounts.
Signs of more serious
malnutrition appear when
nutritional reserves are
depleted and nutrient and
energy intake is not
sufficient to meet day-today needs or added
metabolic stress.
 Many malnourished people
live in conditions of
poverty.
Malnutrition also occurs in
our hospitals sometimes.
 For example, acute trauma
or chronic illness, especially
among older persons,
places added stress on
body and energy intake of
these persons is insufficient
to meet their needs.
Overnutrition is a state
that results from excess
nutrient and energy
intake over time.

Obesity may be
another form of
malnutrition,
especially when excess
calorie intake
produces harmful
gross body weight.
Most of the developed countries
of the world have established
standards for the major nutrients
to serve as guidelines for
maintaining healthy populations.


These guidelines serve as a
reference for intake levels of
the essential nutrients to
adequately meet the known
nutritional needs of most
healthy population groups.
In the U.S. these standards are
called the Dietary Reference
Intakes (DRIs).



Recommended Dietary
Allowances (RDAs)recommended daily allowances
of nutrients and energy intake
for population groups
according to age and sex.
Estimated average requirement
(EAR)- intake level that meets
the need of ½ of the
individuals in a specific group.
The quantity is used to
develop the RDA.
Adequate Intake (AI)-a guide
when there is not enough
scientific evidence available to
establish the RDA figure.
Food Guide Pyramidhas provided a simple
practical nutrition tool,
even for young children
in elementary schools.
Serves as the basis for
general meal planning
and evaluating a
person’s overall foodintake pattern.

Components added in
2005:
◦ vertically-banded
food groups
◦ discretionary calories
◦ physical activity
Based on individual
needs
 Professionals must
remember that
regardless of the type
of food guide or
recommendations
used, patterns vary
with individual:
needs,
tastes,
habits,
living situations, and
energy demands.
