Principles of nutrition Flashcards Preview

Nutrition > Principles of nutrition > Flashcards

Flashcards in Principles of nutrition Deck (101)
Loading flashcards...
1
Q

Good nutrition

A

Good health
Prevention of disease
Recovery from illness

2
Q

Nutrition

A

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

3
Q

Nutrients

A

‘Materials’
Substances digested, absorbed, promote body function
Carbohydrate, fat, protein, vitamins, minerals, water

4
Q

Essential nutrient

A

Substance necessary for life, cannot be synthesised by body, must be in diet

5
Q

Food

A

Substance eaten, digested and absorbed

Provides at least one nutrient - appropriate?

6
Q

Diet

A

Foods selected

‘balanced’=adeqaute amounts of all nutrients

7
Q

Malnutrition

A

Incorrect amount of one or more nutrients in diet (not just lack)

8
Q

Undernutrition

A

lack of proper nutrition, caused by not having enough food or not eating enough food containing substances necessary for growth and health

9
Q

Nutritional status

A

Intake of nutrients vs requirement –> state of health

10
Q

Nutritional assessment

A

Measurement of nutritional status balance

Biochemical and anthropometric data, diet history

11
Q

Dietician

A

Applies science of nutrition to individuals or groups

Health and disease

12
Q

Metabolism

A

Changes constantly taking place in body due to tissue activity, transformation
Nutrients –> metabolism
–> energy liberated
–> tissue formed
–>body functions controlled and stimulated

13
Q

Anabolism

A

Simple molecules –> complex, requires energy

Results in growth

14
Q

Catabolism

A

Complex molecules –> simple, releases energy

Occurs during starvation and illness, energy intake decreases

15
Q

Basic role of carbohydrate

A

Heat and energy

16
Q

Basic role of fats

A

Heat and energy incorporated into body tissue

17
Q

Basic role of protein

A

Tissue formation and repair broken down to produce energy

18
Q

Basic role of vitamins and minerals

A

For regulation of body processes incorporated into tissue (minerals)

19
Q

Basic role of water

A

Temperature regulation
Waste product excretion
Fluid medium essential for metabolism

20
Q

Measurement of nutrients in food

A

E.g. energy

  • calorie (kCal), unit of heat
  • joule (kJ, mJ), unit of heat/ muscular/ electrical energy
  • measured by oxidation of food
21
Q

Nutrient requirements

A

COMA Report

SACN 2000

22
Q

COMA Report

A

Committee on Medical Aspects of Food Policy Report (1991)

  • dietary reference values for food energy and nutrients in the UK]
  • estimated average requirement (EAR)
  • reference nutrient intake (RNI)
23
Q

SACN 2000

A

Scientific Advisory Committee on Nutrition
Advises PHE etc. on nutrition and related health issues
-reviews on vit A, iron, energy requirement, carbohydrates and health, vit D (2016), folic acid (2017)

24
Q

Carbohydrates

A

Consist of C, H and O
Foods of plant origin e.g. grain, fruit, vegetables
CO2 + H2O –> sugar and starch
Monosaccharides, disacchardies, polysaccharides

25
Q

Monosaccharides

A

Simplest form of carbohydrates

e.g. glucose, fructose, galactose

26
Q

Disaccharides

A

Pairs of carbohydrate molecules

e.g. sucrose, lactose, maltose

27
Q

Polysaccharides

A

Complex form of carbohydrates

e.g. starch (amylose - straight chain and amylopectin - branched)

28
Q

Source of glucose

A

Made from starch

Found in fruit e.g. grapes

29
Q

Source of fructose

A

Found in honey, fruits

30
Q

Source of sucrose

A

Made from beet and cane

Found in fruit and vegetables

31
Q

Source of lactose

A

Found in mammalian milk

32
Q

Source of maltose

A

Found in sprouting grain

33
Q

Source of starch

A

Storage carbohydrate in plants

Found in grains (++), potatoes, peas, beans, lentils

34
Q

Source of galactose

A

Made from digestion of lactose

Not naturally occurring

35
Q

Source of glycogen

A

Stored form of carbohydrate found in liver and muscles

Not found in meat, destroyed during hanging process

36
Q

Non-starch polysaccharides

A

Dietary fibre: no enzymes so not digested , but for bulk, peristalsis , excretion; removed from refined carbohydrate food
Made from plant cell walls
Found in cereals, vegetables

37
Q

Non-starch polysaccharides advantages

A

Bulky and take longer to eat
Prolonged feeling of fullness as stay in stomach longer
Prevent constipation, colonic cancer
-NSP and carcinogens: binds, dilutes by > faecal bulk, < transit time therefore < exposure

38
Q

Non-starch polysaccharides disadvantages

A

Bind to minerals (Ca, Fe) –> deficiencies
Wind from metabolism of NSP in saecum and colon:
-methane, CO2, H2
-depending on type of NSP and bacterial flora
Insufficient energy intake: bulky and take longer to eat

39
Q

Carbohydrate digestion

A

Broken down by enzymes (e.g. salivary amylase) to monosaccharides
Starch - longer digestive process
Disaccharides more readily absorbed (quicker energy source)

40
Q

Carb release from liver

A

Metabolised for energy e.g. glucose only for brain, NS, RBCs
Converted into glycogen, stored in muscles and liver
Converted into fat when glycogen stores are full

41
Q

Glycaemic index

A

GI 1-100
Ranks carbohydrates
Rate at which carbohydrate reaches bloodstream as glucose
Important to maintain blood sugar level 3.5-10mmol/l (hormonal control)

42
Q

Low glycaemic index

A

Slow and steady release, levels constant and stable

< insulin resistance and weight control

43
Q

Less carbohydrate leads to

A

More fat metabolism (ketoacidosis)

Depletion of body tissue (protein)

44
Q

Carbohydrate in our diet

A

40-80% of energy intake
Foods cheap, plentiful, palatable, easy too prepare, low fat content
Starch(64%)>sucrose>lactose>fructose(3%)
High fibre, slow release - regulate blood sugar
Can also contain vitamins, minerals, some protein and fat

45
Q

Guidelines: sugars

WHO March 2015

A

Free sugars
<10% strong recommendation (12 tsps/dy)
<5% conditional recommendation
Reduce throughout life course

46
Q

Guidelines: sugars

SACN July 2015

A

Commissioned by DH and FSA
Recommended <5% free sugars
Average intake is ~11.5% (adults) therefore considerable challenge; great changes in dietary behaviour
-food labels display total sugar

47
Q

Free sugar

A

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

  • replaces Non-Milk Extrinsic Sugar and ‘added’ terms
  • does not include lactose in milk and milk products
48
Q

“trends”

A

Sugar - current baddie
Fat/ carbohydrate debate (>obesity, >diabetes)
Is sugar the culprit?
Rising levels of heart disease (CVD) in 60s - Seven Countries Study
Current concern with impact on general and long term health, as well as (well known) dental impact

49
Q

Seven Countries Study

A

Data not included of high fat, low heart disease and vice versa; plus not separate sugar
‘Fat makes you fat’; manufacturers low fat products (5% not low), with sugar substituted for taste

50
Q

John Yudkin 1972

A

Sugar consumption
‘new’ vs fat
Current concern with impact on general and long term health, as well as (well known) dental impact

51
Q

Fats

A
Consist of C, H and O (patterns and proportions)
Fatty acids (sat, monounsat, polyunsat) + glycerol --> triglyceride
52
Q

Saturated fat

A

Butter, cheese, full-fat milk, pizza, takeaways, pies

53
Q

Monounsaturated fat

A

Olive, nuts, avocado

54
Q

Polyunsaturated fat

A

Omega 3: oily fish, soya bean

Omega 6: sunflower seeds, wheat germ, corn

55
Q

Trans fatty acids

A

Hydrogenated

In frying and baking fats

56
Q

Essential fatty acids

A

For structure and function of cell membranes
To regulate cholesterol metabolism
Vegetable and marine oils

57
Q

Sources of fat

A

Meat, dairy, eggs, vegetables (e.g. olive, coconut oils)

58
Q

Cholesterol

A

LDL, HDL
From diet and synthesised in body
Associated with animal tissues
-full-fat dairy products, fatty meat, egg yolks, offal

59
Q

Oils

A

Fats that are liquid below 20 degrees

60
Q

Digestion of fats

A

Digestion in stomach and small intestine

Broken down to constituents, may reform as triglycerides

61
Q

Functions of fats

A

Energy for tissue activity and body T maintenance
Incorporated into body structure e.g. brain and nervous tissue
Hold position and protection of vital organs
Insulation (subcutaneous heat loss)
Satiety - presence in duodenum delays stomach emptying
Provide fat-soluble vitamins and assist absorption

62
Q

Fats body stores

A

Under skin and around abdominal organs (interchanged not inert, mobilised for fuel)

63
Q

Dietary component of fat

A

~35% of energy intake from fats
70-95g/day
20-30g/day sat

64
Q

Proteins

A

Main constituent of every living cells
Consist of chains of amino acids
CO2 + H2O + nitrogen-containing compounds (N and mineral elements e.g. iron) –> amino acids –> peptides, proteins
Peptides and proteins can convert to amino acids by transamination in liver

65
Q

Proteins found in

A
Meat (myosin)
Fish
Eggs (albumin)
Cheese
Milk (caesin)
Nuts
Pulses e.g. lentils, beans
Cereals e.g. wheat (gluten)
RNI 45-55g/ day
66
Q

Essential amino acids

A

Can’t be made

67
Q

Functions of proteins

A

Replacement during metabolism and wear and tear
-e.g. hair, nails, skin, digestive secretions, bone, dentine, epithelium, antibodies
New tissue production e.g. growth, recovery from injury, pregnancy, lactation
Forming enzymes, hormones
Energy source

68
Q

Digestion of proteins

A

Into amino acids and dipeptides and tripeptides

69
Q

Fate of proteins

A

Structural proteins, converted into other aas, oxidised for energy

70
Q

Vitalamine

A

Rice - beriberi in chickens (funk, 1911)

71
Q

Vitamin C

A

Citrus fruit juice

Sailors’ scurvy (Lind, 1753)

72
Q

Vitamins

A

Organic (or related) substances with specific biochemical functions
Essential for normal metabolism (promote reaction/s)

73
Q

Sources of vitamins

A

In diet (e.g. Vit C only)
Some manufactured if enough precursor (pro-vitamin)
-beta carotene –> vit A
-vit D (diet) made in body, converted in skin by UV irradiation (for CA metabolism)
-vit K and some of B group vits made by intestinal bacteria (+ diet)

74
Q

Water-soluble vitamins

A

Excreted, not stored

C and B group

75
Q

Fat-soluble vitamins

A

Harmful as stored

A, D, E and K

76
Q

Requirement of vitamins

A

Not known exactly (varies between people)
COMA: recommendation meet requirement of average healthy person
SACN: RNI for vitamins and minerals 2002-2017

77
Q

Minerals

A

~3% of body weight
Essential constituents of soft tissues, fluids, skeleton, teeth
Incorporated into enzymes, proteins and soluble salts
Many sources

78
Q

Examples of minerals

A

Calcium, sodium, potassium (bananas), iron (e.g. fruit and veg), zinc
-haemoglobin = iron-containing oxygen-transport metallo-protein

79
Q

Water

A

~65-70% of body weight
Fluid medium for almost all body processes
Intra- and extra-cellular fluids
Body secretions, excretions
Sufficient urine flow, prevention of constipation
Joint lubrication
T control (lung and skin evaporation)
Death after a few days (compared to protein, fat, carb reserves)

80
Q

Sources of water

A
Beverages (milk, tea)
Fruit and veg (80-90%)
Bread (~35%)
Fish (65%)
Meat (50-70%)
81
Q

Metabolism to water

A

Protein, fat, carb –> water in hibernation

82
Q

Water loss

A

Urine, faeces, sweat (lose salt), exhaling, vomiting, diarrhoea, haemorrhage, exudate from burns

83
Q

Water balance

A

Thirst, kidney regulation

84
Q

Water intake

A
  1. 5-3l/day
    - climate and activity
    - drinks (1L), food (1L), metabolism (0.5L)
85
Q

Too much water

A

Kidneys can’t keep up excretion
Blood diluted, lower salt concs
Water moves from blood to cells & organs
Brain swells and prevents vital functions

86
Q

Ecstasy

A

–> thirst and >ADH

87
Q

Marathon runners

A

Over consumption and retention of water, plus sweat and salt loss

88
Q

Energy

A

From oxidation of carbohydrates, fats, protein and alcohols in diet
Needed for
-growth and maintenance of body tissues
-maintenance of body T
-voluntary and involuntary muscle movement (heart, GIT, respiration)

89
Q

1g carbo

A

16kJ
4kCal
Most efficient source

90
Q

1g fat

A

37kJ

9kCal

91
Q

1g protein

A

17kJ
4kCal
Takes time to turn into energy, needs energy

92
Q

1g alcohol

A

29kJ

7kCal

93
Q

Basal metabolism

A

Amount of energy required for basic processes e.g. heartbeat, respiration, cellular activity

94
Q

Healthy balanced diet

A

Lots of fruit and veg (40%)
Starchy staple foods (wholemeal bread, wholegrain cereals, including B vits and fibre) 40%
Protein rich foods (lean meat, fish, eggs, lentils)
Some dairy foods (pref. lower fat variety)

95
Q

Food Standards Agency Guidelines

A

Base meals on starchy foods
7 portions of different fruit and veg per day
2 portions of fish per week including 1 portion oily fish
Cut down sat fat and sugar
Eat less salt (<6g/day)
Get active and try to be a healthy weight
Drink plenty of water
Limit alcohol intake

96
Q

Diet for treatment of disease

A

Diabetes, gluten sensitivity

97
Q

Diet-related disease

A

Diet is the cause
>/< nutrient (e.g. scurvy, fat-soluble vitamins)
Dietary toxins (e.g. hydrocarbons from smoking processes)
Contaminated food (bacteria, pesticides, heavy metals)

98
Q

Diet-associated disease

A

Diet is a contributory factor
< Infectious diseases - hygiene, antibiotics
> degenerative disease - CVD, malignancies, linked to diet

99
Q

Dentist’s role

A

DBOH

  • healthier eating advice
  • good dietary practice guidelines
100
Q

Diet and disease

A

WHO/FAO
“Diet, nutrition and the prevention of chronic diseases”
-obesity, type 2 diabetes, cancer, CVD, dental diseases, osteoporosis
-diet (and exercise) throughout life can reduce threat of global epidemic (remember ageing)

101
Q

Other considerations

A
Pesticides and organic produce
Additives, fortification
Dried foods
Processed foods (and lifestyle)
GM foods
Cooking effects, food storage
Alcohol -carb content; energy source; damage to liver, brain
Food supplements
Food labelling (RDAs/GDAs)
-complex