principles of nutrition

Question 1

What is the FSAs mission?

Answer 1

To have food we can trust-
~safe
~is what it says
~consumers- informed choices and access to affordable diet

Question 2

What is the definition of nutrition?

Answer 2

Sum of processes for living organism to receive+use materials from environment to promote its own vital activities

Question 3

What are nutrients and therefore food?

Answer 3

Substances digested, absorbed to promote body function
Eg. Carbs, fat, protein, vitamins, minerals, water

Food provides at least one nutrient

Question 4

What is an essential nutrient?

Answer 4

Necessary for life but can’t be synthesised

Question 5

What is diet?

Answer 5

Foods selected to be eaten

Aim- balanced diet

Question 6

What is malnutrition?

Answer 6

Incorrect amount of one or more nutrients in diet

Undernutrition- lack of nutrients

Question 7

What is our nutritional status?

Answer 7

Balance of intake and requirement of nutrients to result in the state of health
Measured by nutritional assessment
Dietician- applied science of nutrition in health and disease

Question 8

What is metabolism?

Answer 8

Changes constantly taking place in body due to to tissue activity and transformation

Question 9

What is anabolism and catabolism?

Answer 9

Anabolism- simple—>complex molecules requiring energy and resulting in growth
Catabolism- complex—>simple molecules releasing energy and occurs during starvation and illness

Question 10

What do carbohydrates do?

Answer 10

Metabolised for energy (brain, nervous system, RBCs)
Converted into glycogen (muscle and liver stores)
Converted into fat (when stores are full)

Question 11

What do fats do?

Answer 11

Energy for tissue activity
Body temp maintenance 
Incorporated into body structure
Structure and function of cell membranes
Regulates cholesterol metabolism
Holds in position and protects organs
Insulation
Satiety (fat in duodenum delays stomach emptying)
Provides fat soluble vitamins and assists absorption

Question 12

What do proteins do?

Answer 12

Replaced during metabolism and wear and tear
New tissue production
Forms enzymes and hormones
Energy source

Question 13

What do vitamins and minerals do?

Answer 13

Vitamins
~regulates body processes
Minerals
~incorporated into enzymes, proteins and soluble salts
~essential constituents of soft tissue, fluid, skeleton

Question 14

What does water do?

Answer 14

65-70% body weight
Fluid medium for metabolism
Intra/extra-cellular fluids
Body secretions, excretions
Sufficient urine flow
Prevents constipation 
Joint lubrication
Regulates temperature

Question 15

How are nutrients measured in food?

Answer 15

Energy- measured by oxidation of food
Calorie (kCal)- unit of heat
Joule (kJ, mJ)- unit of heat/muscular/electrical energy

Question 16

What are non-starch polysaccharides?

Answer 16

Made from plant cell walls and forums in cereals, veg and fruit
- dietary fibre
No enzymes so not digested
Used for bulk and important for peristalsis and excretion
Refined carb food has this removed

Question 17

What are the advantages and disadvantages of non-starch polysaccharides?

Answer 17

Advantages 
~bulky- takes longer to eat
~longer feeling of fullness
~prevents constipation
~prevents colonic cancer (binds to carcinogens, dilutes by increasing faeces, less transit time so less exposure
Disadvantages
~binds to minerals so cause deficiencies
~produces wind from metabolism in caecum and colon (methane, CO2, H2 depending on type of NSP and bacterial flora)
~insufficient energy intake

Question 18

What is the glycaemic index?

Answer 18

1-100 (ranks rate at which carb reaches blood stream as glucose)
Blood sugar should be 3.5-10mmol/l
Low GI- slow and steady release, lvls stable, weight control, less insulin resistance
Recent research- diff for individuals and affected if combined

Question 19

What happens if there’s less carb intake?

Answer 19

More fat metabolism (but too much could lead to ketoacidosis)
More protein depletion of body tissue

Question 20

What level of energy intake should be from carbs?

Answer 20

40-80% (90-120g)
<10% of total energy intake should be from free sugars and <5% conditional recommendation which should be reduced throughout life
1g carb=16kJ (4kCal)

Question 21

What are free sugars?

Answer 21

Added, plus naturally present in honey, syrup, unsweetened fruit juice

Question 22

What are examples of carbohydrates?

Answer 22

.

Question 23

What are examples of fats?

Answer 23

Fatty acids
~saturated- butter, cheese, milk, pizza, pies
~monounsaturated- olives, nuts, avocado
~polyunsaturated- omega 3 (oily fish, soya bean), omega 6 (sunflower seeds, wheat germ, corn)
Trans fatty acids
~hydrogenated- frying and baking fats, baked goods, long shelf life

Question 24

Where is fat stored?

Answer 24

Subcutaneously and as visceral fat (around abdominal organs)

- it’s constantly interchanged and mobilised for fuel)

Question 25

What level of energy intake should be from fats?

Answer 25

~35% (70-95g/day of which 20-30g/day is saturated)

1g fat=37kJ (9kCal)

Question 26

What are examples of proteins?

Answer 26

Meat (myosin)
Eggs (albumin)
Milk (caesin)
Wheat (gluten)

Side note- AA’s can’t be made but can be converted via transamination in liver

Question 27

What level of energy intake should be from proteins?

Answer 27

45-55g/day

1g protein=17kJ (4kCal)

Question 28

How might vitamins be manufactured?

Answer 28

If there’s enough precursor eg. Beta carotene—> Vit A
Or Vit D converted in skin by UV irradiation
Vit K and some Vit Bs made by intestinal bacteria

Question 29

What vitamins are water/fat-soluble?

Answer 29

Water-soluble- excess is excreted
~C and B
Fat-soluble- stored so can be harmful
~A, D, E and K

Question 30

How much water do we need?

Answer 30

2.5-3l a day conditional

Drinks (2L), food (1l), metabolism (0.5l)

Question 31

What happens if too much water is consumed?

Answer 31

Blood becomes diluted so lower salt conc
Water moves from blood to cells and organs
Brain swells and prevents vital functions

Question 32

What is basal metabolism?

Answer 32

Amount of energy required for basic life processes

Question 33

What does a healthy balanced diet involve?

Answer 33

Lots of fruit and veg
Starchy staple foods
Protein rich foods
Some dairy foods