Nutrition in health and disease Flashcards
what is the definition of a nutrient requirement
that amount required to sustain life and prevent a deficiency
intake must = demand
what are the fixed components of nutrient demand
basal requirements
- membrane functions (pumps, transport, signalling)
mechanical work
- cellular level
- tissue level
what are the variable components of nutrient demand
Cost of processing the dietary intake
Cost of Physical activity
Cost of maintaining body temperature
Cost of growth
what is the basal metabolic rate
the rate of energy expenditure per unit time
i.e. the amount of energy per unit time that a person needs to keep the body functioning at rest
how can we measure basal metabolic rate
calorimetry
usually calculated on lean body mass - various adjustments for activity and illness
BUT easy to over estimate requirements
what can failure to meet nutritional requirements lead to
development of deficiencies
weight loss
development of excess
obesity
define malnutrition
As state of nutrition in which a deficiency or excess (or imbalance) of energy, protein, and other nutrients, causes measurable adverse effects on tissue / body form, (body size, shape, composition) body function and clinical outcome
also includes micronutrients
how can malnutrition be identified clinically
marasmus
kwashiorkor
obesity
what is marasmus
form of severe malnutrition characterised by protein deficiency - look emaciated
what is kwashiorkor
form of severe protein-energy malnutrition characterized by edema, and an enlarged liver with fatty infiltrates - enlarged abdomen
different from marasmus because of sufficient calorie intake but insufficient protein consumption
what does over nutrition lead to
obesity - leads to longer term health problems that are often hidden and only become apparent over time
**trouble in store
what does under nutrition lead to
weight loss and impaired function - strongly associates with illness
i.e. cause of under nutrition frequently disease related
**trouble right now
what BMI classifies you as overweight
> 25
what BMI classifies you as obese
> 30
what are three causes of obesity
environment
lack of exercise
genes
what metabolic syndromes can develop from obesity
Hypertension. Cardiovascular disease. Type II diabetes mellitus. Fatty liver. NASH Cirrhosis
what cancers can develop from obesity
breast
bowel
what BMI classifies you as underweight
<20
what BMI classifies you as having a physical impairment
<18
what BMI is associated with increasing severe consequences
<16
what factors can cause undernutrition
environmental appetite failure access failure disease intestinal failure
why is BMI not enough to determine if someone has under or over nutrition
an obese patient can become undernourished as weight loss is a hallmark of undernutrition
5% loss of body mass (unintentionally ) can occur quickly
10% loss of body mass becomes associated with increasing morbidity
what is used to screen for undernutrition
MUST - malnutrition universal screening tool
picks up patients at risk
what is the first step in MUST
height weight BMI - <20 score 1 - <18 score 2
what is the second step in MUST
have you lost weight unintentionally in the last 3-6 months
yes 5% score 1
yes - 10% score 2
what is the third and final step in MUST
has the patient eaten in the last 5 days
no - score 2
how do you interpret MUST scores and
score over 2 suggests a risk of undernutrition
score 1: supplements and watch
score 0: Monitor
what are other factors that can be associated with malnutrition aside from illness
social isolation
age
socially vulnerable groups
what are the clinical consequences of malnutrition
- Impaired immune response
- Reduced muscle strength
- Impaired wound healing
- Impaired psycho-social function
- Impaired recovery from illness and surgery
- Poorer clinical outcomes
what should be done once an at patient risk has been identified
Take a history
Examine the patient
- Look at them nutritionally
Analyse what the problem is
Work out their requirements
- nitrogen, fluids, vitamins, minerals, trace elements
Refer to dietician
what are reasons for appetite failure in undernutrition
anorexia nervosa
disease related
what are reasons for access failure in undernutrition
teeth
stroke
cancer of head and neck
head injury
how can intestinal failure cause undernutrition
Reduction in the functioning gut mass to below the minimal amount necessary for adequate digestion and absorption of nutrients
if a patient has access failure malnutrition how can this be managed
help with eating
- purees, soups, yogurt, juices, liquids, etc
Fine bore nasogastric tube
Percutaneous Endoscopic Gastostomy
if a patient has intestinal failure malnutrition how can this be managed
assess nutritional requirements
establish IV feeding
deal with sepsis urgently
? small amounts enteral feeding
