Body Composition/Nutrition

Question 1

Define body composition

Answer 1

The relative proportions of protein, fat, water and mineral components in the body that make up total body weight

Question 2

What are the 2 components of body composition?

Answer 2

Fat free mass FFM = 72% water, 21% protein, 7% bone minerals

Fat mass FM = 20% water, 80% adipose tissue

Question 3

What are 2 types of body fat distribution, sex they’re found in and what they can predispose

Answer 3

Andoid: upper body obesity mainly around stomach area, seen in males, higher risk for T2DM, CVD

Gynoid: lower body obesity, harder on hip and knee joints, seen mostly in women

Question 4

What are 3 different body types?

Answer 4

Ectomorph: lean, long limbs, narrow waist, weight loss easy

Mesomorph: strong athletic slim hips, fast metabolism, gain muscle mass easily, lose weight easily

Endomorph: round short tapering limbs, larger boned, larger thighs, round face, easily build muscle but weight loss difficult

Question 5

How do measurements of body weight and body composition differ?

Answer 5

Body composition = assessment of varying components of FFM compared to FM

Body weight = total weight of FFM + FM

Question 6

What does BMI measure? What are its constraints?

Answer 6

Ratio of height to weight

Doesn’t consider body composition, should be used in conjunction with other measures (weight circumference), age and gender independent

Question 7

What are the different classifications of BMI?

Answer 7

Underweight <18.5
Normal 18.5 - 24.9
Overweight 24.9 - 29.9
Obese >30

Different cutoffs for Asian populations - normal and overweight cut offs are lower

Question 8

What are other ways you can measure BMI?

Answer 8

Ulna length
Demi span (jugular notch -> end of palm)
Knee height calliper
Mid upper arm circumference

Question 9

What does a MUAC of <23.5 and >32cm indicate?

Answer 9

<23.5 cm = BMI <20kg/m2

>32cm = BMI >30 (obese)

Question 10

What are 4 methods of measuring body composition?

Answer 10

Anthropometry
Densitometry
Bioelectrical impedance
Imaging techniques

Question 11

How can you measure muscle function?

Answer 11

Hand grip
Indicates general upper body strength
Muscle functions responds earlier to nutritional deprivation than muscle/body mass

Question 12

Outline anthropometry (skin fold measuring)

Answer 12

Estimates volume of subcutaneous fat

Assumes constant ratio of subcutaneous fat and total fat

Question 13

What are some populations of at risk waist measurements?

Answer 13

Subsaharan African, Eastern Mediterranean, Middle eastern men
South asian, japanese and chinese men
All women

Question 14

Outline densitometry

Answer 14

Under water weighing
Measures percentage body fat
Hard in young, old, sick
Need to breathe out as much as possible

Question 15

Outline bioelectric impedance

Answer 15

Non invasive bedside measure
Works on premise that fat doesn’t contain water and electrical current flows through tissues containing water and ions but not fat

Limitations: assumes hydration of FFM is constant, not efficient in extremes of BMI, dehydration or ascites, may be affected by skin temperature

Question 16

In obesity what cancers are you at greater risk of?

Answer 16

Uterus
Kidney
Gallbladder
Liver

Question 17

Outline the MUST

Answer 17

Malnutrition Universal Screening Tool

All patients should be screened within 24 hours of hospital admission

Question 18

What’s cachexia and its symptoms?

Answer 18

A condition of abnormally low weight, weakness and general bodily decline associated with chronic disease - disproportionate loss of skeletal muscle rather than body fat (associated with cancer)

Weight loss
Muscle atrophy
Fatigue
Weakness
Loss of appetite

Question 19

What are some consequences of relative loss of lean muscle mass?

Answer 19

Impaired immunity
Increased infection
Decreased healing
Weakness, infection, pressure sores
Pneumonia (usually death follows)

Question 20

What are some consequences of malnutrition?

Answer 20

Reduced quality of life
Increased risk of infection
Increased pressure sore/wound then delay in healing
Medication less effective
Longer hospital stays
Increased falls
Confusion
Reduced respiratory muscle strength = SOB
Increased mortality risk

Question 21

What factors affect body composition?

Answer 21

Biological: age, gender, genetics, ethnicity, menopause
Lifestyle: diet, exercise, smoking, alcohol
Health related factors: presence of disease, genetic predisposition
Biometric: height, fat, muscle distribution

Question 22

What is nutrition?

Answer 22

The science of food and its relationship to health

Question 23

What factors affect basal metabolic rate?

Answer 23

Fever
Stresses/illness
Malnutrition
Fasting/starving
Nicotine/caffeine
Height, gender, size, age, body composition
Sleep
Environmental temperature

Question 24

What are the 6 essential nutrients?

Answer 24

Water
Calories - carbs, fat
Protein - amino acids
Essential fatty acids
Vitamins
Minerals

Question 25

What’s the role of fat?

Answer 25

Maintain healthy skin and hair
Insulate body organs against shock
Maintain body temperature
Promoting healthy cell function
Storage of vitamins

Question 26

What are the fed, fasting and starved states?

Answer 26

Fed 0-4 hours after food
Fasting 4-12 hours after food
Starved 12+ hours

Question 27

What are glucose, fatty acids and amino acids used for in the fed state?

Answer 27

Glucose -> glycogen stores
Fatty acids -> body fat stores
Amino acids -> protein synthesis

Question 28

What’s the difference in energy supply between fasting and starved states?

Answer 28

Fasting:
Glycogen stores -> glucose -> energy for brain, NS, RBCs
Body fat stores -> fatty acids -> energy for other cells

Starved:
Body protein -> amino acids -> glucose
Body fat stores ->fatty acids
Amino acids + fatty acids = ketone bodies which provide energy for NS/cells