E8. Energy balance and measurements Flashcards
Describe energy balance
one note
There is a need to maintain energy balance to prevent:
-Unintentional weight loss -associated with increased morbidity and mortality
-Overfeeding can cause immediate and serious derangements in biochemistry
Positive energy balance?
Obesity development
Growth
Pregnancy
Recovery from depletion
Negative energy balance?
Wasting disease
Anorexia
Voluntary weight loss
Starvation
3 major sources of energy expenditure in the body are?
-Basic Metabolic rate (BMR)- rel. constant
-Thermic effect of food- 10% of energy expenditure- rel. constant
-Physical activity- variable
An individual’s energy expenditure is determined by?
Body size
Body composition
Age
Sex
Climate
Genetics
Psychological state
Disease processes
Hormones
Estimation of energy requirements using rule of thumb equation?
one note
Resting energy expenditure (REE) will only provide enough energy to maintain basic functions, you also need energy for?
-activity
-maintaining temperature
-growth and repair
Physical Activity Level (PAL) calculation
one note
Injury factor effect on basic metabolic rate?
-Injury or fever increases the BMR
eg 1oC rise in body temperature
- BMR increases by 10%
-Similar changes with eg surgery burns
-Level of energy required depends on degree of injury
REE with illness?
one note
How to assess nutritional status (ABCD)?
Anthropometry- height, weight, subcutaneous fat etc
Biochemical and haematological parameters
Clinical and physical assessment
Dietary intake
How to assess nutritional status (anthropometry)?
-Height,
-weight (current, history, what is % weight loss)
-Body Mass Index (BMI)
-waist circumference or girth
-Skinfolds e.g. triceps- measure of subcutaneous fat
BMI indications?
one note
BMI and ethnic groups?
-No consensus in whether > risk of obesity between Asians and Caucasians
-Studies suggest increased prevalence in black adults.
BUT BMI may underestimate obesity in some groups:
-Cut off point in South Asians 23 (27.5 for obesity).
-South Asian adults > waist circumference
And > skin folds
Biochemistry assessment?
plasma proteins, electrolytes, vitamins, lipids
Disease specific indicators?
Haematology- Full blood count
Clinical & Physical Assessment?
Muscle strength (grip)
Ability of wounds to heal (pressure sores)
Appearance
Mobility
Can they feed themselves?
Other clinical considerations?
-Evidence for malnutrition- what severity?
-Are there any specific nutritional problems relating to the presenting medical condition(s).
-Are there any increased nutritional requirements? eg surgery, burns
-Are there increased nutrient losses?
-What are the effects of any medication?
