AS Lecture 18 - Nutrition

Question 1

What is malnutrition?

Answer 1

Often refers to undernutrition resulting from inadequate consumption, poor absorption or excessive loss of nutrients -> but cn also encompass overnutrition from overeating or excessive intake of specific nutrients

Question 2

Problems in malnutrition facts:

Answer 2

1 in 3 of global popn live below recommended nutritional needs. Half of western society is overweight and 25% obese -> accounts for most T2DM, 30-40% CVD and is the largest risk factor for cancer. Many chronic diseases common in west are related to nutrition

Question 3

How is body mass assessed?

Answer 3

BMI is a clinically relevant method of estimating adiposity OR waist measurement

Question 4

What are the values for BMI levels?

Answer 4

40 morbidly obese

Question 5

How is undernutrition measured?

Answer 5

Monitor body weight BUT can be complicated by fluid balance OR arm circumference

Question 6

What is body weight a reflection of?

Answer 6

Total cell mass

Question 7

Why can, in some cases of malnutrition, body weight not be reflective of nutritional status?

Answer 7

Oedema confounds body weight

Question 8

What are dietary reference values?

Answer 8

Reflect the nutritional needs of a popn -> they are a way of assessing nutritional adequacy

Question 9

Why are dietary reference values needed?

Answer 9

Many different nutrients are needed to maintain health and reduce risk of diet-related diseases -> different requirements of nutrients are needed at different stages of life

Question 10

What is Vitamin C used for?

Answer 10

Essential in man -> is an anti-oxidant (converts Fe3+ to Fe2+) and it’s important in formation of collagen

Question 11

What is a deficiency of Vit C called?

Answer 11

Scurvy

Question 12

What does EAR, RNI and LRNI mean?

Answer 12

EAR: Estimated average requirement (mean) RNI: Reference nutrient intake (2.5 s.d. above EAR) LRNI: Lower RNI (2.5 s.d. below EAR)

Question 13

How can the nutrients in the body be used effectively?

Answer 13

Demand for energy needs to be met first -> basic survival

Question 14

What does energy in equal in stable weight?

Answer 14

Energy in = energy out + energy stored

Question 15

What does energy equal in weight gain and why?

Answer 15

Energy in exceeds energy out due to increase intake, decreased expenditure and decrease in metabolic rate

Question 16

How is energy spent in the body?

Answer 16

x

Question 17

What is RNI?

Answer 17

Level at which most nutritional recommendations are set

Question 18

What 3 components make up your energy expenditure?

Answer 18

Basal metabolic rate, adaptive thermogenesis and exercise

Question 19

What are the 5 fates of acetyl CoA?

Answer 19

Pyruvate, amino acid, fatty acid, TCA, ketone bodies

Question 20

Where is glycogen stored?

Answer 20

In the liver and muscle

Question 21

What does adipose tissue store?

Answer 21

Lipids and is a major store

Question 22

What is stored in muscle and why?

Answer 22

Glycogen due to periods of prolonged starvation

Question 23

Why are fat stores not very well autoregulated?

Answer 23

Due to oxidation hierarchy, fat sparing occurs, so there is no adjustment of oxidation to intake

Question 24

What is the body composition of a 70 kg man?

Answer 24

Question 25

How does growth occur in humans?

Answer 25

Humans increase in weight 20x from baby to adult and all material in weight gain enters body as food/drink

Question 26

How does body composition change from foetus to adult man (w/obese man as well)?

Answer 26

Question 27

What are some peripheral signals that regulate appetite?

Answer 27

Question 28

What complications relative to loss of lean body mass can occur?

Answer 28

Question 29

What does severe malnutrition in childhood cause?

Answer 29

Delays in chemical maturation and can effect IQ

Question 30

What are the causes of undernutrition in the developing world?

Answer 30

Politics, climate, poor water, poor agricultural policy, demand of developed world, food security will become the biggest public health issue in the coming years

Question 31

What are the causes of undernutrition in developed countries?

Answer 31

Age, change in social circumstances (isolation, death of a partner, poor housing), illness, 10% of free living elderly people are undernourished to a degree that their function is effected

Question 32

What are some signs of undernutrition?

Answer 32

Weight loss, loss of subcutaneous fat, muscle wasting, peripheral oedema, glossitis (cracking on edges of mouth), hair loss, chronic infections, poor wound healing, chronic wounds, pressure sores, listless, apathetic, recurrent pulmonary infections

Question 33

What are the 2 mechanisms for energy restriction/starvation?

Answer 33

x

Question 34

How does the body function when it is nonstressed in terms of CHO, fat and protein metabolism?

Answer 34

Question 35

How does the body function when it is stressed, due to a short fast, in terms of CHO, fat and protein metabolism?

Answer 35

Question 36

What are the symptoms/effects of marasmus?

Answer 36

General energy deficit, growth failure, no oedema, uncommon to have mental changes and good appetite

Question 37

What are the symptoms/effects of kwashiorkor?

Answer 37

Relative protein deficit, growth failure, oedema, mental changes, poor appetite

Question 38

What is thiamine used for?

Answer 38

Free thiamine (in body) and as TMP, TTP, TPP. It is critical for release and utilisation of energy from food and nerve function

Question 39

What is Beriberi?

Answer 39

NS ailment caused by deficiency of thiamine in the diet as thiamine helps breakdown energy molecules (glucose) and found in membranes of neurons

Question 40

What are the symptoms of beriberi?

Answer 40

Severe lethargy and fatigue, complications affecting CVS, NS, muscular system and GIS

Question 41

Why is beriberi important?

Answer 41

Thiamine occurs in unrefined cereals and fresh foods so people whose diet consist of white polished rice have low thiamine -> chronic alcoholics and gastric bypass surgery are important

Question 42

What is niacin used for?

Answer 42

Nicotinamide is derivative of niacin and used by body to form coenzyme NAD and NADP

Question 43

What is a deficiency of niacin?

Answer 43

Pellagra