6 - General Nutrition

Question 1

What is metabolism?

Answer 1

The chemical processes that occur within a living organism in order to maintain life

Question 2

What are anabolic and catabolic processes?

Answer 2

Question 3

Why do we need energy?

Answer 3

• Mechanical work
• Transport work
• Biosynthetic work
• Electrical work

Question 4

How is ATP produced?

Answer 4

Oxidation of:
- Lipids

• Alcohol
• Carbohydrates
• Proteins

Question 5

What is the SI unit of food energy?

Answer 5

kJ (1000J)

1kCal = 4.2 kJ

(when packets say 100 cal, they actually mean 100kCal)

Question 6

What is the definition of a kCal?

Answer 6

Amount of energy required to raise the temperature of 1kg of water by one degree celsius

Question 7

What do we need in our diet and what is essential?

Answer 7

- Carbohydrates - energy

- Protein - energy and aa

- Fat - energy and essential

- Minerals - essential

- Vitamins - essential

- Water

- Fibre - GI function

Question 8

What is the general structure of carbohydrates?

Answer 8

(CH₂O)

Contain ketone and aldehyde groups and multiple OH’s

Question 9

What is a dextrin?

Answer 9

Oligosaccharide (3-12 units)

Question 10

Why is cellulose essential and why can’t we digest it?

Answer 10

• Needed for GI function
• Used to lower cholesterol and risk of diabetes
• Low fibre intake associated with bowel cancer and constipation
• We don’t have enzymes to hydrolyse b 1-4 linkages

Question 11

What are the three disaccharides and what are they made of?

Answer 11

• Sucrose (glucose and fructose)
• Lactose (glucose and galactose)
• Maltose (glucose and glucose)

Question 12

What amino acids are essential?

Answer 12

If Learned This Huge List May Prove Truly Valuable ​

• Isoleucine
• Leucine
• Threonine
• Histidine
• Lysine
• Methionine
• Phenylalanine
• Tryptophan
• Valine

Question 13

What are conditionally essential amino acids?

Answer 13

Not always essential but under certain circumstances they are (e.g illness and stress) as there is a high rate of protein synthesis

e.g pregnant women and children need some tyrosine, arginine and cysteine

Question 14

Why do vegetarians sometimes have illness?

Answer 14

• Can’t get all essential amino acids from a single plant like you can with single bit of meat
• Need wide variety of plant sources as vegetarian

Question 15

What are lipids composed off and why are they essential?

Answer 15

• Triacylglycerols

(more reduced than carbohydrates so release more energy)

• Needed for absorption of fat soluble vitamins (A,D,E,K)
• Provide essential FA, linolenic and linoleic acid

Question 16

Why is linolenic acid essential?

Answer 16

Used to make phospholipids

Question 17

What minerals are essential and what for?

Answer 17

Question 18

To maintain water and electrolytes in the body what is recommended to administer IV?

Answer 18

Water: 30ml/kg/day

Na/K/Cl: 1mmol/kg/day each

Question 19

What vitamins are essential and what do they cause if there is a deficiency?

Answer 19

In tiny quantities

- A: Xerophthalmia (dry eye)

- D: Rickets

- E: Neurological abnormalities

- K: Defective blood clotting

Question 20

What is hypervitaminosis?

Answer 20

Intake of too much vitamins

Usually due to supplements

Question 21

What are some water soluble vitamins?

Answer 21

Question 22

What should be our daily intake of fibre?

Answer 22

18g a day

(usually lower than this on average in real population)

(found in veg, cereal foods)

Question 23

What are dietary reference values (DRV)?

Answer 23

Estimates published by SACN of the amount of energy and nutrients needed by different groups of healthy UK population, replaced RDA

Question 24

What is the Daily Energy Expenditure?

Answer 24

BMR_(~1700) + DIT_(~150) + PAL_(~1000-3000)

• 58kg woman - 9,500 kJ/day
• 70kg man - 12,000 kJ/day

Question 25

What does the BMR use energy for and what factors affect BMR?

Answer 25

Used for ion transport and biochemical reactions in cells - **Gender** **- Environment** **- Body size** **- Body temperature** (10% increase per 1 degree) **- Endocrine status** (hyperthyroidism) **- Lactation and prengancy**

Question 26

How do PAL affect energy expenditure?

Answer 26

Sedentary- 30kJ/kg/day Moderately active - 60kJ/kg/day Very active - 100kJ/kg/day

Question 27

What organs make up BMR?

Answer 27

Skeletal muscle - 30% Liver - 20% Brain - 20% Heart - 10% Other - 20% (maintaining body temp)

Question 28

What is the theoretical energy component in each food group of our diet?

Answer 28

Question 29

How do you calculate BMR?

Answer 29

If not overweight, 100 x weight (kg)

Question 30

How do you work out DIT?

Answer 30

10% of the energy intake

Question 31

Where are energy stores in the body?

Answer 31

- Creatine Phosphate in muscle (few seconds worth) - Glycogen in liver^100g and muscle^300g - Excess fat stored in adipose tissue (40 days worth) - Protein last resort

Question 32

What is the body weight made up of in a 70kg man and a 100kg man?

Answer 32

Question 33

What is obesity?

Answer 33

Chronic disease where there is excess fat in adipose tissue that impairs health, BMI \> 30 ## Footnote - Cancer - Gallbladder disease - Type II diabetes - Hypertension - CVD - Osteoarthiritis

Question 34

How do you calculate and interpret BMI?

Answer 34

Question 35

What is an alternative measurement to BMI?

Answer 35

**Waist:Hip ratio** \>0.9 (m) \>0.85 (f) obese - More fat on waist than hips leads to risk of stroke, type 2 diabetes, hypertension

Question 36

How would you work out the rate of weight loss for someone who has a daily energy expenditure of 12,000 kJ stopped eating?

Answer 36

Would mobilise fat stores (37kJ/g) 12,000/37 = 324g/day x 7 = 2.3kg/week

Question 37

Who does the eatwell plate not apply to?

Answer 37

- Children under two - Malnourished people - Special dietary needs

Question 38

What is malnutrition and how is it measured?

Answer 38

Imbalance between what an indiviual eats and what the individual requires for sustained health **MUST (high) -** Inpatients, Outpatients, GP, care homes Malnourished patients spend longer in hospital

Question 39

What can malnutrition be caused by?

Answer 39

**Undernutrition:** Anorexia, Bulimia nervosa, Lack of food in developing countries **Malabsorption:** Coeliac's and Crohn's disease

Question 40

How much water do we need to drink a day?

Answer 40

- 2.5 litres lost to faces, urine and expiration - Metabolism produces 350ml - We need to drink the rest (2.2 litres)

Question 41

How much is one unit of alcohol?

Answer 41

10mg alcohol Half a pint, small glass of wine 14 units a week, over three days and at least two days alcohol free

Question 42

What would you do if someone was malnourished in hospital?

Answer 42

- Allow them to eat lots of what they like at first - Fortisip

Question 43

What is Marasmus?

Answer 43

Question 44

What is Kwashiorkors?

Answer 44

Question 45

What are the differences between Marasmus and Kwashiorkor's?

Answer 45

Question 46

What is refeeding syndrome?

Answer 46

When you eat a lot after not eating for a while, leads to **convulsions, coma, death, confusion**. Due to **ammonia toxicity** as there is a downregulation in enzymes of the urea cycle Refeed at **5-10kcal/kg/day over a week** - Cancer patients, anorexic patients, post surgery, alcoholics

Question 47

How would you refeed someone with Kwashiorkor's and Marasmus?

Answer 47

**Marasmus:** Slowly, small amounts carefully monitored **Kwashiorkor's:** Small amounts of proteins at regular intervals. Can't have lots as there is a downregulation of enzymes in urea cycle so leads to build up of ammonia which is toxic

Question 48

What is Starling's law of the capillary?

Answer 48

Question 49

What happens to excess amino acids in the blood?

Answer 49

Excreted in the urine

Question 50

Why is there muscle wasting and fatigue in a child with Marasmus?

Answer 50

- Energy intake is less than energy requirement - Protein from muscles is broken down into amino acids for gluconeogenesis

Question 51

Why is there oedema in Kwashiorkor's but not Marasmus?

Answer 51

Kwashiokor is a protein deficiency but Marasmus is a energy deficiency so Marasmus adapt and can produce lipo-proteins with low levels of everything. Kwashiokor cannot produce lipoproteins as low protein so lipids build up in the liver, leading to an enlarged liver and hypoalbuminimea

Question 52

Why do malnourished people have a poor immun system?

Answer 52

Don't have the amino acids to produce antibodies