nutrition pdf - غير معروف

Nutritional diseases

Nutrition and Nutrients



Nutrients

are substances that must be supplied by

the diet because they are not synthesized in the body in
sufficient amounts.

The need is depend :



Age



physiological state

Nutrition and Nutrients

macronutrients



Carbohydrates



Fats



Proteins

micronutrients


Vitamins



Minerals



Water

The energy balance

The

energy intake

equal to

energy output

The major components of energy output are:

1. resting energy expenditure (

REE

) (

BMR

) (60%)

depend on FFM (total body mass- fat mass)

2. physical activity (30%)

3. Diet induced thermo-genesis (10%)

Downloaded from: StudentConsult (on 17 October 2011 08:27 PM)

The energy balance

Energy intake depend on macronutrient content

Different energy densities:

carbohydrates

(4 kcal/g),

fat

kcal/g) and

protein

(4 kcal/g).

The average energy intake is about

2800

kcal/d (2000-3500)

for men and about

1800

kcal/d(1600-2250)for women

Downloaded from: StudentConsult (on 17 October 2011 08:27 PM)

Response to under- and over-nutrition

under-nutrition                          over-nutrition

        BMR
    energy preserved                        BMR

low insulin

energy consumed

glycogen depletion

high insulin

    the triglyceride depletion             increase fat store
                                                           as triglyceride

    the protein breakdown                   disease state

Carbohydrates

• Carbohydrates are the

sugars

and

starches

found in foods.

• There are two general types of carbohydrates:

simple

and

complex

• At least

55%

of total calories should be derived from

carbohydrates.

( 100-200 g/ d )

• No

individual carbohydrate is an essential nutrient as

carbohydrates can be synthesized de novo from protein.

Simple Carbohydrates

These sugars are

fructose

and

glucose

(found in fruits and

vegetables,

lactose

(found in milk), and

sucrose

(table sugar).

• The most important to the body is

glucose

– the form of the

sugar that goes directly to the bloodstream and

• provides quick energy. All other sugars must be changed into

glucose by the body before the cells can use them. The cells
use glucose as their primary source of energy. Glucose that is
not needed immediately is converted by body to

glycogen

, a

form of starch stored in the muscles and liver.

Complex Carbohydrates

• Starches

are complex

carbohydrates that are made up
of many units of glucose. These
chains must be broken down by
the body into single units of
glucose before they can be used.
simple sugars.

Breads, cereals,

and potatoes

contain starch.

• Dietary Fiber

is another complex

carbohydrate, which comes from
non-digestible part of plants.
There two types of dietary fiber:

soluble

and

insoluble

. Soluble

fiber combines with waste to
assist in their removal.

( bran,

beans, apples, carrots, and other
vegetables)

• Insoluble fiber absorbs water

and helps to provide needed
bulk to the diet.

(whole grains

and the skins and seeds of fruits
and vegetables).

DIETARY CARBOHYDRATES

Free sugars

Monosaccharides :Glucose, fructose

Disaccharides : Sucrose, lactose, maltose
fruits, milks, vegetables

Starch polysaccharides

: Cereals (wheat, rice), root

vegetables (potato), legumes (lentils, beans,
peas)

Non-starch polysaccharides

: (NSP, dietary fibre)

Plants Cellulose, Hemicellulose

Fats (Lipids)

•

Fats

are the nutrients that contains the most

concentrated form of energy.

•

Fatty acids

have the highest energy density of

the macronutrients (9 kcal/g)

•

30%

of calorie should be derived from the fat

• Fats

are part of many body tissues and are

important as carriers of other nutrients, such
as vitamins. Fats also carry the flavor of foods
– making foods tastier.

Types of Fats

•

Saturated fats

are usually

solid at room

temperature. They

contain maximum number

of hydrogen atoms.

butter, and animal fats

tend to be high in

saturated fats.

• A diet high in saturated

fats can lead to an

increased chance of

coronary artery disease.

•

Unsaturated

fats are those

fats that are liquid at room

temperature.

• Olive oil and peanut oil

• Fish oils and most

vegetables oils, such as

corn, soybean, and

sunflower oils.

Protein

•

Proteins

are substances found in every cell. The body needs

proteins to build and repair all body tissues. Proteins are made up
of basic units called

amino acids

• There are

20 different amino acids

. Nine of them are essential,

and the other eleven amino acids can be

• produced by the body.

10 – 15

% of energy derived from it.

•

Complete proteins

Incomplete proteins

Legumes cereals roots

eggs milk and meat

Nutrients that Regulate

•

Vitamins, minerals,

and

water

are nutrients that

work with the energy-providing nutrients to be sure that

the body functions properly.

• Water is the most vital nutrient because it provides the

means for all other nutrients to be carry throughout the

body.

• Vitamins, minerals, are not digested by our body, and

they do not provide Calories. They work with

carbohydrates, fats, and proteins to promote growth and

regulate body processes.

Vitamins

they also help

change
carbohydrates and
fat into energy.

• Because the body

cannot make most
vitamins, they must
be supplied by the
foods .

•

Vitamins

are organic

substances with the key
roles in certain metabolic
pathways.

Water-soluble Vitamins

•

Water-soluble vitamins :

Thiamin (B1),

Riboflavin (B2), Niacin, Vitamin B6, Folate
(Folic acid), Vitamin B12, Pantothenic acid ,
biotin, choline Vitamin C (Ascorbic acid).

• Fat- soluble vitamins:

vit A, vitD , vitE , vitK

Minerals

• Minerals

are simple substances found in the

environment that are essential to the body’s
functioning.

• Minerals

are used to regulate a wide range of

body processes, from bone formation to blood
clotting.

• Most

minerals

are either quickly used or lost

in waste products, therefore we must eat
mineral-rich foods daily to replenish our
supply. Iron is an exception –it tends to be
kept and recycled by the body.

Major Minerals:

calcium, phosphorus, magnesium,

potassium, sodium .

• Calcium

keeps the nervous system working well

and is needed for blood clotting. Osteoporosis is
disease caused by calcium deficiency.

• Sodium

and

potassium

help regulate the passage

of fluids in and out of cells. Too much sodium in
the diet may aggravate high blood pressure or
hypertension, increasing the risk of heart attack,
stroke or kidney disease. Table salt is one source
of sodium in the diet.

Trace Minerals:

iron, iodine, manganese, zinc, copper, and fluorine

• The majority of the minerals needed for the body to function

are only required in very small, or trace amounts.

• Iron is a vital part of hemoglobin – a substance in red blood

cells that carries oxygen to all parts of the body. Insufficient

iron may cause anemia.

• Iodine is needed for the thyroid gland to function properly.

The thyroid gland produces hormones that control how

quickly chemical reactions occur in our body. Too little iodine

– thyroid gland enlarged. The primary sources are seafood

and iodized table salt.

Standards of Nutrition

• Dietary Reference Intakes (DRIs)

– Quantitative estimates of nutrients

collectively for proper function and health

• Recommended Daily Allowances (RDA)

• The average daily dietary intake that meets
the nutrient requirement of nearly all

healthy persons of a specific sex, age, life
style or physiological condition.

The Food Guide Pyramid

Fig 18.2

Malnutrition

Definition

loss of the lean body mass and adipose tissue

due to insufficient dietary supply

primary

: inadequate or poor-quality food intake (war or

famine).

secondary

: from diseases that alter food intake or

nutrient requirements, metabolism, or

absorption.

Two syndrome

kwashiorkor (malnutrition with edema)
marasmus (malnutrition with marked muscle-wasting).

CAUSES OF malnutrition

Decreased the energy intake ( hypo metabolism)



Economic

: poverty, famine



anorexia :

nervosa, dementia ,depression

cancer , renal failure



Abdominal pain

: pancreatitis, intestinal

ischemia



Impaired diet transit

: benign and malignant

esoph.

or gastric obstruction



Maldigestion

: pancreatic exocrine

insufficiency, short bowel

syndrome



Malabsorption

: small intestinal disease(celiac

disease

Causes of malnutrition

Increased energy expenditure (hyper metabolism)



Increased BMR

: (thyrotoxicosis , fever, cancer

trauma , sepsis, surgery,burn)



Excessive physical activity

( marathone runner )



Acute and chronic inflammation

: T.B

,collagen diseases.



Energy loss

:(e.g. glycosuria in diabetes)

Mixed mechanisms



Disseminated cancer



Chronic inflammatory bowel disease (crohns

disease

Consequences of malnutrition

Wt loss

Weakness

Loss of cell

mediated immunity Bronchopneumonia

Too week to walk

Urinary tract

infection

Too week to sit

Bed sore

death

Metabolic response to the Starvation

First day:

• Circulating glucose and FA and TGs , liver and muscle glycogen

(1200 Kcal ).

• Lipolysis for the FAs production (65% of energy source )

First few days :

• Lipolysis increase and ketone body production

increase

• Gluconeogenesis begin (70 g),15% from protein

2 weeks-30 days

• Energy conserved , BMR decrease , thyroids hormones

decrease , sympath. system decrease

• Lipolysis continue 150g/day (90% on fat)
• Muscle PTN breakdown decrease(20g/day)

Metabolic response to stress

• High catecholamines ,glucagon , cortisol

cytokines , TNF , int 1,6

• Skeletal and visceral PTN catabolism (150 g/d)

• 50 % of body protein stores within 3 weeks

Physiological consequences

1. GIT :



Atrophy of small IN. mucosa



Gastric and pancreatic secretion



Volume of bile and conjugated bile acids decrease



Carbohydrate. and fat malabsorption decrease.

2.CVS:



Myocardial Mass and function decrease

3.Immune system



Lymphocyte count decrease



Delayed skin hypersensitivity



Decrease production of ABs

4.Respiratory:

• Structural and functional atrophy

5.Bone marrow

• Decrease lymphocyte and WBC and RBC

6.Renal :

• Decrease mass and function

7.Skin and hair:

• Dry ,thin, wrinkled , hyperkeratosis
• Wound healing

8.Endocine

    Low insuline
    Increase cortisol
    Increase growth homone
    T3and t4 decrease
    Primary gonadal  dysfuction

Clinical features:

 WT loss
 Weakness and, craving for food
 muscle wasting
 Loss of subcutaneous fat
 Leg edema and ascites
 Skin dry pale lax,  easy packable thin hair
 amenorrhea or impotence
  Bradycardia Cold cyanosed extremities, pressure sores
 distended abdomen, with diarrhea
 apathy, depression, loss of the initiative
 Features of associated vitamins deficiency
 susceptibility to infections

INFECTIONS ASSOCIATED WITH PEM Patients

• Gastroenteritis
• Gram-negative septicemia
• Respiratory infections, especially

bronchopneumonia

• viral infection :herpes simplex
• Tuberculosis
• Streptococcal and staphylococcal skin

infections

• Helminthic infestation

Nutritional Assessment

• History

• Physical examination

• Anthropometric measurements

• Laboratory investigations

• Functional test

Nutritional Assessment

History

Dietary Analysis
 Dietary history Review foods eaten
 Review preparation methods
 Evaluate digestive and absorption adequacy
 Review supplements taken



Significant weight loss within last 6 months

 > 10% loss of body weight
 <90% 0f ideal body weight

patient History of Weight Loss

Finding

Example

Involuntary diet restriction

Poverty due to inadequate income

Anorexia

Anorexia nervosa, severe depression,

dementia, cancer, chronic renal failure

Inadequate diet selection

Chronic alcoholism, strict vegetarianism

Critical illness

trauma, burn, major surgery, sepsis

Dysphagia

Esophageal obstruction

Nausea, vomiting

Gastric or intestinal obstruction

Chronic abdominal pain

chronic pancreatitis, intestinal angina

Chronic diarrhea

Pancreatic, intestinal mucosal

Physical Examination



Evidence of muscle wasting



Depletion of subcutaneous fat



Peripheral edema, ascites



Skin changes (easily plucked hair)



Features of Vitamin deficiency



e.g. nail and mucosal changes

Nutritional Assessment

Anthropometry



Weight for Height comparison



Body Mass Index(BMI)



Triceps-skin fold

< (6mm for the men), <(8mm for the women)



Mid arm muscle circumference

<(20cm for the men),<(18.5cm for the women)

Nutritional Assessment

     BODY MASS INDEX (WEIGHT/HEIGHT2)

   BMI (kg/m2)

classification

> 25

obese

>20

Adequate nutrition

18.5-20

Marginal

< 18.5

Malnutrition

17-18.5

Mild

16-17

Moderate

< 16

Severe

Lab investigations

1. Serum visceral protein:



albumin < 30 mg/dl



transferrin < 150 mmol/l



pre-albumin <12 mg/dl

Nutritional Assessment

2. vitamin and minerals assays:



tests reflecting specific nutritional deficits

e.g. prothrombin time

3.Assessment of immune function:



Total lymphocyte count < 1800 / mm3



Skin anergy testing

Nutritional Assessment

Functional test



Hand grip dynamometry

Other

Urinary creatinine excretion:

1g of urine creatinine:18.5g of FFM

23mg/kg of ideal body wt./men

18mg/kg of ideal body wt./women

bioelectric impedance analysis

Nutritional therapy

• Provide a life sustained therapy for the

patient who can not take adequate food by
mouth who consequently at risk for
malnutrition and its complication

Benefits of Nutritional Support

• Preservation of nutritional status

• Prevention of complications of protein

malnutrition

•



Post-operative complications

Nutritional therapy given when

• 1. improve the quality of life.
• 2. improve the ability to recover from the

disease.

Don’t forget it depend

: disease outcome

severity of the

malnutrition

any additional stress
risk of nutritional therapy

Who Requires

Nutritional Support?

• Patients already with malnutrition –

surgery / trauma/sepsis

• Patients at risk of malnutrition

Patients at Risk of Malnutrition

Cannot eat for >9 days

Vomiting

: acute pancreatitis

,hperemesis gravidarum

GIT obstruction

: malignancy

neurological :

coma , swallowing dis.

Abdominal pain

: A. pancreatitis

Can not absorb

: intestinal fistula ,short

bowel syndrome

Should not eat

: bowel rest in

a.pancreatitis

Intestinal fistula ,crohns disease

• Others

nutritional support in patient with malignancy

nutritional support in malnourished patient

before surgery

Type of the nutritional

rehabilitation

• Normal diet

mild malnutrition and

treatable disease

• Supplement

high energy and protein

content used if normal

diet

cant give

sufficient nutrition

• Specific Nutritional support

Enteral feeding

Parentral feeding

Types of Nutritional Support

Enteral Nutrition

Parenteral Nutrition

Enteral Feeding Is Best

• More physiologic
• Less complications
• Gut mucosa preserved
• No bacterial infection
• Cheaper

Enteral Feeding Is Indicated

• When nutritional support is

needed

• Functioning gut present

• No contra-indications

– no ileus, no recent anastomosis, no

fistula

Types of Feeding Tubes

• Naso-gastric tubes
• Naso-duodenal

tubes

• Naso-jejunal tubes

Tubes inserted down the upper GIT,

following normal anatomy

Types of Feeding Tubes

• Gastrostomy tubes

– Percutaneous Endoscopic Gastrostomy (PEG)
– Open Gastrostomy

• Jejunostomy tubes

Tubes that require an invasive

procedure for insertion(feeding for long time)

Downloaded from: StudentConsult (on 29 October 2011 12:19 AM)

What Can We Give

in Tube Feeding?

Blenderised feeds

Commercially prepared feeds

• e.g. Vivonex

Complications

of Enteral Feeding

12% overall complication rate

• Gastrointestinal complications
• Mechanical complications
• Metabolic complications
• Infectious complications

Complications

of Enteral Feeding

Gastrointestinal

• Distension
• Nausea and vomiting
• Diarrhoea
• Constipation

Complications

of Enteral Feeding

Infectious

• Aspiration pneumonia

• Bacterial contamination

Complications

of Enteral Feeding

Mechanical

• Malposition of feeding tube
• Sinusitis
• Ulcerations / erosions of nasal and esoph
• Blockage of tubes

Parenteral Nutrition

Allows greater caloric intake

BUT

• Is more expensive
• Has more complications
• Needs more technical expertise

Who Will Benefit From

Parenteral Nutrition?

Patients with/who

– Abnormal gut function
– Cannot consume adequate amounts of

nutrients by enteral feeding

– Are anticipated to not be able to eat

orally by 5 days

– Prognosis warrants aggressive nutritional

support

Two Main Forms of

Parenteral Nutrition

• Peripheral Parenteral Nutrition
• Central (Total) Parenteral

Nutrition

Peripheral Parenteral Nutrition

Given through peripheral vein
• Short term use
• Mildly stressed patients
• Low caloric requirements
• Needs  large amounts of fluid
• Contraindications to central TPN