E8 Energy balance and nutritional status

Question 1

equation for energy balance

Answer 1

energy intake stress - energy expenditure = change in energy

Question 2

inequality for positive energy balance

Answer 2

energy intake > energy expenditure

Question 3

inequality for negative energy balance

Answer 3

energy intake < energy expenditure

Question 4

what is meant by a negative energy balance?

Answer 4

more energy being used through exercise and metabolism than energy being consumed through food

Question 5

there is a need to maintain energy in clinical practice to prevent what?

Answer 5

• unintentional weight loss associated with increased morbidity and mortality
• overfeeding can cause immediate and serious derangements in biochemistry (increases risk of CVD and diabetes)

Question 6

reasons for and results of positive energy balance

Answer 6

• obesity development
• growth in children and adolescents
• pregnancy
• recovery from depletion (after a period of negative energy balance)

Question 7

reasons for and results of negative energy balance

Answer 7

• wasting disease
• anorexia
• voluntary weight loss
• starvation

Question 8

what are the 3 major sources of energy expenditure in the body?

Answer 8

• basal metabolic rate (BMR)
• thermic effect of food
• physical activity

Question 9

what is BMR in terms of energy expenditure?

Answer 9

• energy that we require to keep ourselves functioning
• this is relatively constant day to day but changes slightly with age

Question 10

what does physical activity vary between?

Answer 10

• day to day
• varies between patients

Question 11

what are daily variations in energy needs mainly down to?

Answer 11

changes in physical activity

Question 12

what foods are more palatable and appealing?

Answer 12

those with a greater energy density

Question 13

state 9 things that determine an individual’s energy expenditure

Answer 13

body size
body composition
age
sex
climate
genetics
psychological state
disease processes
hormones

Question 14

how does age contribute to the determination of an individual’s energy expenditure?

Answer 14

older people need less energy

Question 15

how does climate contribute to the determination of an individual’s energy expenditure?

Answer 15

cold environments require generation of heat to stay warm which requires energy

Question 16

how do genetics contribute to the determination of an individual’s energy expenditure?

Answer 16

can influence basal metabolic rate

Question 17

how does psychological state contribute to the determination of an individual’s energy expenditure?

Answer 17

if mental health declines, appetite can decline

Question 18

other than the BMR, what else is energy needed for?

Answer 18

food digestion
activity
maintaining temperature
growth and repair

Question 19

what does REE stand for?

Answer 19

resting energy requirement

Question 20

what does REE include?

Answer 20

• basal metabolic rate and energy required for processing of food and functioning
• doesn’t include energy requirements for physical activity

Question 21

what equations should be used to estimate REE for patients with a BMI over 30?

Answer 21

Mifflin-St Jeor (MSJ) equations

Question 22

what are the MSJ equations for men and women?

Answer 22

Question 23

what must happen after energy requirements have been calculated with the MSJ equations for patients?

Answer 23

• patient must be monitored
• if they start to gain or lose weight, requirements should be altered
• MSJ equations only provide best guess

Question 24

what does physical activity include?

Answer 24

• posture, job, leisure / voluntary activity
• added together, these make up overall physical activity level

Question 25

what does an individual's PAL depend on?

Answer 25

physical activity level depends on how active a patient is

Question 26

what is the PAL value for in-patients?

Answer 26

- 1.25 - takes into account that they may be doing a little bit of activity (sitting up, walking down the corridor etc.) but not exercising or playing sport

Question 27

what does injury factor do to BMR?

Answer 27

- injury factors / fever increases BMR - similar changes with surgery, burns etc. - level of energy required depends on degree of injury

Question 28

who needs more energy, ill people or healthy people? explain why

Answer 28

- ill people have an increased REE but do less physical activity - this means they still need less energy than healthy people overall

Question 29

what things should be noted surrounding energy balances?

Answer 29

- type of food intake is as important as amount of food - a small positive energy balance over a long period can lead to obesity - an individual's energy intake and expenditure are constantly changing and may need regular reassessment

Question 30

how should nutritional status be assessed?

Answer 30

ABCD - Anthropometry (height, weight subcutaneous fat etc) - Biochemical and haematological parameters - Clinical and physical assessment - Dietary intake

Question 31

what is meant by anthropometry in nutritional status assessment?

Answer 31

- height - weight (current, history, what is % weight loss?) - BMI - waist circumference or girth - body composition (skin folds)

Question 32

what demographic do studies suggest have an increased prevalence of obesity?

Answer 32

black adults

Question 33

what may BMI underestimate in some groups? explain

Answer 33

- obesity - cut off point in asians 23 (27.5 for obesity) - south asian adults > waist circumference and > skin folds

Question 34

explain how biochemistry and haematology are used to assess a patient's nutritional status

Answer 34

biochemistry - general (plasma proteins, electrolytes, vitamins, lipids) - or disease speicific indicators haematology - full blood count (looks for things such as anaemia)

Question 35

state things that may be considered in a clinical and physical assessment to determine a patient's nutritional status

Answer 35

- muscle strength - ability of wounds to heal (eg. pressure sores) - appearance - mobility - can they feed themselves? - evidence of malnutrition? severity? - specific nutritional problems? - any increased nutritional requirements? - increased nutrient losses? - impaired nutrient digestion and absorption? - effects of any medication? eg. reduced appetite

Question 36

how can muscle strength be assessed for nutritional status assessment?

Answer 36

- grip strength - measured using callipers - sit up and stand up test

Question 37

how can dietary intake be assessed for determining a patient's nutritional status?

Answer 37

measurement of current food intake - food diaries - 24 hour food recall - food frequency questionnaires changes in appetite - duration / severity