Nutrition in Health and Disease Flashcards
Diet
Sum total of all foods ingested
Food
The individual items ingested
Nutrients
Chemically defined compounds required by the body
What influences our choice of food?
- Likes/dislikes
- Religious and ethical considerations
- Social and psychological components
What is the required amount of nutrition equal to?
The amount required to sustain life and prevent a deficiency
What makes up the fixed component of demand?
- Basal requirements
- Mechanical work
- Substrate turnover
What basal requirements are there?
Membrane function including pumps, transport and signalling
At what level can there be mechanical work?
- Cellular level
- Tissue level
What makes up the variable component of demand?
- Cost of processing the dietary intake
- Cost of physical activity
- Cost of maintaining body temperature
- Cost of growth
How can basal metabolic rate be measured?
Direct colorimetry
What is basal metabolic rate dependent on?
Lean body mass
What equations can be used to calculate basal metabolic rate?
- Schofield
- Harris Benedict
- Henry
What has to be taken into consideration when calculating basal metabolic rate?
Adjustments for factors such as activity and illness
What contributes to metabolic demand?
Many systems
What is responsible for supply?
The gut and its associated organs
Nutritional failure
Failure to meet the nutritional requirements of the individual and may include the development of deficiency (weight loss) or excess (obesity)
Give 3 examples of forms of malnutrition.
- Marasmus
- Kwashiokor
- Obesity
Malnutrition
A state of nutrition in which an imbalance of energy, protein and other nutrients, causes measurable adverse effects on tissue/body form, (body size, shape, composition) body function and clinical outcome
What can malnutrition include?
Not only protein energy malnutrition but also malnutrition of other nutrients, such as micronutrients
What law are we bound by?
First law of thermodynamics: we cannot make or destroy energy
What does over-nutrition lead to?
- Obesity which leads to longer term problems
- These are often hidden and only become apparent over time
What does under-nutrition lead to?
- Weight loss and impaired function
- It strongly associates with illness
What is often the cause of under nutrition?
Illness
How do you calculate a BMI?
Weight (kg)
_________
Height^2 (m)
How is over nutrition defined?
- BMI>25 overweight
- BMI>30 obese
What are 3 factors affecting obesity?
- Environment
- Exercise
- Genes
What metabolic syndromes can affect obesity?
- Hypertension
- CVD
- Type II diabetes mellitus
- Fatty liver
- NASH
- Cirrhosis
What cancers are linked to obesity?
- Breast
- Bowel
What causes are linked to under nutrition?
- Partly environmental
- Mostly disease related
How is under nutrition defined?
- BMI<20 underweight
- BMI< 18 physical impairment
- BMI<16 increasingly sever consequences
What is a hallmark of under nutrition?
Weight loss
What percentage loss of body mass is associated with increasing morbidity?
10%
Why is BMI not a good indication if a patient is under nourished?
An obese patient who becomes ill can be under nourished but their BMI will not reveal that
What screening is there for under nutrition?
Malnutrition universal screening tool (MUST)
Who can carry out MUST assessments?
People without specialist training
What does MUST identify?
Patients at risk of malnutrition
What is step 1 in the MUST assessment?
- Height
- Weight
- BMI (if <20 then score 1) (if <18 then score 2)
What is step 2 in the MUST assessment?
- Have you lost weight unintentionally in the last 3-6 months
- Yes 10% score 2
- Yes 5% score 1
What is step 3 in the MUST assessment?
- Has the patient eaten in the last 5 days?
- No score 2
How are the results analysed of the MUST assessment?
- A score over 2 suggests a risk of under nutrition
- Score 1: supplements and watch
- Score 0: monitor
What is associated with malnutrition?
- Illness
- Social isolation
- Age
- Socially vulnerable groups
- People affected by ‘food deserts’
Explain the term ‘food deserts’
Limited choice of food due to inability to access wider ranges (limited access to shop, no internet, immobility)
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 are the consequences for under nutrition?
- More care at home
- More hospital admissions
- Longer length of stay
- More GP visits, antibiotics etc.
What is the first stage in treating someone with under nutrition?
- Take a history
- Examine the patient
- Analyse what the problem is
- Work out their requirements
What is the easy method for treating a patient with under nutrition?
Refer the patient to a state registered dietitian
What are possible causes of under nutrition?
- Appetite failure
- Access failure
- Intestinal failure
What can appetite failure be due to?
- Anorexia nervosa
- Disease related
What can access failure be due to?
- Teeth
- Stroke
- Cancer of head and neck
- Head injury
Intestinal failure
Reduction in the function gut mass below the minimal amount necessary for adequate digestion and absorption of nutrients.
What can be the solution for people who require nutritional help?
- Fine bore nasogastric tube
- PEG
What is involved in percutaneous endoscopic gastrostomy?
- Patient sedated
- Endoscopy carried out
- Needle and guide ire into stomach
- Tube pulled back down and out of skin
- Can be placed radiologically
What are the advantages of PEG?
- Can last 18 months without replacement
- Can be used at home
What are the disadvantages of PEG?
- Safe but carries definite risks
- Still an operative procedure
- Difficult ethical issues
