Week 10

Question 1

Nutrition

Answer 1

Process by which the body uses food
Can affect health now and in the future
Has a role in health

Question 2

Nutrients

Answer 2

=Food is the major source
of all nutrients our body
=What are their three main roles:
=Build and maintain body tissues, hormones, enzymes, etc.
=Regulate body functions.
Supply energy for body functions and physical activity.

Essential and non-essential nutrients.
Each nutrient has specific functions; however, all nutrients work together. (Food first approach before multivitamins etc)
Too much or too little of one nutrient affects the others.
The Dietary Reference Intakes (DRIs) are the amounts of nutrients needed each day.

Answer 3

RDA = Recomended daily amount
RDI= recommended daily intake
DRV= dietary reference values
EAR= estimated average requirement
RNI= reference nutrients intake
LRNI= lowest reconvened nutrient intake

Question 4

Estimated Energy Requirements for Adults

Answer 4

Men = 2600 kcals/ day sacan
Womens 2080

Question 5

What is the National Diet and Nutrition Survey (NDNS)?

Answer 5

A national survey of the dietary habits and nutritional status of the UK population aged 18 months and over.
• Dietary habits:
• the foods people eat
• the nutrients they take in in their food

• Nutritional status
• physical measures (in blood, urine or anthropometry) that reflect how well (or badly)
nourished people are in relation to the nutrients in the diet

• in blood and urine these can be:
• concentrations of nutrients themselves • products of their metabolism
• functional processes they regulate.

Question 6

Macro nutrients Carbohydrate (CHO)

Answer 6

CHO: 4kcals/g
• DRV for CHO: 50% of total food energy - no exact
value as depends on energy requirement/intake.
• Non-starch polysaccharide (NSP/fibre): 30g/day (NHS)

Energy Requirement
50% of food energy as CHO

2000 kcals/day
250g/day

Monosaccharides
One Sugar Molecule
• Same Chemical Formula
• Different Structure
• Effects Sweetness and Absorption

• Disaccharides
• Simple Carbohydrates • i.e. Sugars
Two Sugar Molecules
• Maltose = Glucose + Glucose • Sucrose = Glucose + Fructose • Lactose = Glucose + Galactose

• Polysaccharides
• Complex Carbohydrates
• i.e. Glycogen, Starch, Fiber

Many Sugar Molecule
• Glycogen= storage form alpha bond , branched
• Starch- plants
• Fiber
Beta bonds

Question 7

Metabolism

Answer 7

Making Glucose From Protein
• Protein can be converted to glucose
• If carbohydrate inadequate, converts protein to glucose for brain, nerve cells and developing RBCs
• Adequate carbohydrate spares protein

• Converting glucose to fat
• More glucose than needed for energy or glycogen converted to fat and stored

Question 8

Food portions containing 10g CHO

Answer 8

1 small slice bread
• 1 egg sized potato
• 1 tblsp cooked rice
• 1-2tblsp cooked pasta
• 1 Weetabix
• 2 tblsp flaked cereal
• 2-3tblsp cooked pulses
• 2 cream crackers

1 apple
• 1⁄2 banana
• 2 small clementine’s
• 1 scoop ice cream
• 1 digestive biscuit
• 1/3 pint milk
• 1⁄2 glass ordinary cola
• 3 glucose tablets

Question 9

Fiber

Answer 9

Fiber is the structural part of plants and is found in vegetables, fruits, grains and legumes.

• Most dietary fibers are polysaccharides, like starch, but they are not digestible.

• The human body lacks the enzymes needed to digest and absorb fiber.

• As a result fibers reach the lower intestine intact where intestinal bacteria can ferment some fiber.

Question 10

Soluble Fibers

Answer 10

Soluble fibers dissolve in water, form gels and are easily digested by bacteria in the lower intestine.
• Provides a feeling of fullness.
• Slow down the rate food leaves the stomach.
• May have a role with heart disease, diabetes and colon cancer
• Found in legumes and fruits

Question 11

Insoluble Fiber

Answer 11

Insoluble fibers absorb water and swell up resulting in a larger softer stool that is easier and quicker to pass.
• Provides a feeling of fullness
• Helps with intestinal function
• May help with colon cancer
• Found in grains and vegetables

Question 12

Fiber and Health

Answer 12

Both fiber types are important for health.
• Fibers are beneficial for many conditions; constipation, diarrhea, diverticular disease, heart disease, diabetes and colon cancer.
• Fiber is only one factor involved in these conditions.

Question 13

Weight Management

Answer 13

Foods rich in complex carbohydrates tend to be low in fat and added sugars which can help with weight management by providing fewer calories.

• In addition, as fibers absorb water they swell up creating a feeling of fullness and delaying hunger.

Question 14

Non-milk extrinsic sugars (NMES)

Answer 14

CHO so 4kcals/g
• DRV: <10% of total food
energy
• Intrinsic and milk sugars not limited as no adverse effect on health.

Question 15

Health Effects of Sugars

Answer 15

Nutritional deficiencies
• Sugar can only contribute to deficiencies by displacing nutrients.
• Sugars are not “bad” but nutrient dense foods must come first.
• Amount of sugar depends on calories available beyond those needed for nutrients.

Question 16

Gi food

Answer 16

Low gi food 3 hours before game
Need to replenish carbs
HighGi just before

Question 17

Protein

Answer 17

Actual requirement for protein.
• RNI for Adults: 0.75g/kg/day.
Max 1.5- 2g/kg/day.
• UK average intakes are in excess of RNIs.
• Protein: 4kcals/g

Question 18

Amino Acids

Answer 18

There are 20 different amino acids, each with a different side group
• 11 amino acids are nonessential because the body can make them
• 9 amino acids are essential because the body can’t make them. Therefore they must be provided by the diet.

Leucine = protien 3g

Question 19

Proteins

Answer 19

Amino acids are linked end-to-end with a peptide bond in different sequences to form proteins.
• Two amino acids is a dipeptide
• Three amino acids is a tripeptide
• More than three amino acids is a polypeptide

The unique shapes of proteins enable them to perform their various functions in the body.
• Some are hollow balls that carry materials.
• Some much longer than they are wide (tendons).
• Some function as they are; others need other polypeptides to form larger complexes to perform.

When proteins are exposed to heat, acid, or other conditions that disturbs their stability, they denature.
• An example is stiffening of egg whites when whipped

Question 20

Functions of proteins

Answer 20

Building Materials
• Body cells and tissues
• Muscles
• Blood
• Skin
• Hair and fingernails
• Collagen
• bone and tooth matrix
• ligaments, tendons
• wound healing

Enzymes are protein
• Smaller proteins that catalyze (speed up) chemical reactions. Enzymes are needed for most metabolic reactions in body cells.
• Enzymes breakdown substances, build substances and transform one into another.

Some hormones are protein
• Hormones are messengers that turn on
and off many metabolic processes.
• Some examples of protein hormones include:
• Insulin
• Thyroid hormones • Histimine
• Adrenaline
• Serotonin.

Proteins help maintain fluid and electrolyte balance. • Body fluids can flow freely and are contained inside and
outside cells and between cells and within blood vessels. • Proteins are larger and cannot cross freely
• Proteins attract water

Proteins act as carriers or transporters for nutrients and other molecules
• Hemoglobin carries oxygen
• Lipoproteins carry lipids
• Some proteins carry nutrients across cell walls, other carry nutrients in body fluids

Antibodies are proteins
• When the body detects an in invading antigen, it makes antibodies, giant protein molecules designed to combat them.
• Without sufficient protein, the body cannot maintain its antibodies to resist disease.
• Each antibody is designed to destroy one specific antigen.

Blood clotting
• An injury starts a chain reaction leading to production of fibrin, a stringy protein that forms a clot. Protein collagen forms a scar to replace the clot and heals the wound.
• Vision
• Opsin is a light sensitive protein pigment in the retina. It responds to light by changing its shape, initiating the nerve impulses conveying the sense of sight to the brain.

Using Amino Acids to Make Proteins or Nonessential Amino Acids
• If a nonessential amino acid is missing, body cells can make if from another amino acid.
• If an essential amino acid is missing, the body may break down some of its own proteins to obtain it.

Question 21

Fat

Answer 21

Fat: 9kcals/g
• DRVs: Total fat 35% of total food energy – guideline not target/ minimum requirement.
• Saturated fat (SAFA):10% of total energy
• Polyunsaturated fat (PUFA): 6% of total energy
• Trans fat: 2% of total energy

Question 22

Degree of Saturation

Answer 22

Fatty acids can be saturated or unsaturated.
• A saturated fatty acids has all the carbons in the chain
filled with hydrogen’s.
• An unsaturated fatty acid is missing hydrogen’s, and as a
result the carbons bond to each other twice, forming
what is called a double bond.
• One place in the fatty acid missing hydrogen’s the fatty acid is monounsaturated.
• Two or more places in the fatty acid missing hydrogen’s the fatty acid is polyunsaturated.

Location of Double Bonds
• Fatty acids are identified by the position of the double bond nearest the methyl (CH3) end.
• A polyunsaturated fatty acid with its first double bond three carbons away from the methyl end is an omega-3 fatty acid.
• An omega-6 fatty acid is a polyunsaturated fatty acid with its first double bond six carbons away from the methyl end.

Question 23

Essential Fatty Acids

Answer 23

The body can make saturated fatty acids and the body can convert some saturated fatty acids into monounsaturated fatty acids.
• The body cannot make two polyunsaturated fatty acids, linoleic acid (omega-6) and linolenic acid (omega-3), and therefore these are essential and must be provided from the diet.

Question 24

Triglycerides

Answer 24

Fats in our body and in food are made up of fatty acids and glycerol called triglycerides.
• Glycerol is a water soluble compound that can bind to three fatty acids.
• Monoglyceride – one fatty acid on glycerol. • Diglyceride – two fatty acids on glycerol.
• Triglyceride – three fatty acids on glycerol.

Question 25

Solid or Liquid Fats

Answer 25

The relative amounts of different fatty acids effects whether a fat is solid or liquid.

Question 26

Fats in Food

Answer 26

• Foods contain combinations of the three types of fatty acids.
• Completely saturated fats and completely polyunsaturated fats are rare in nature.
• The dominate fatty acid in a food determines whether the fat is refereed to as saturated or unsaturated.

Question 27

Cholesterol

Answer 27

The body needs cholesterol every day.
• Cholesterol serves as the starting material for many important body compounds.
• Bile acids
• Hormones
• Vitamin D
• Cell membranes
• Myelin sheath around nerve fibers
• Cholesterol is synthesized in the liver.

Question 28

Low Density Lipoprotein (LDL) vs High Density Lipoprotein (HDL)

Answer 28

Low Density Lipoprotein (LDL) (bad)
Carry between 60-80% of total serum cholesterol.
• Greatest affinity for cells in the arterial wall – delivers cholesterol to arterial tissue.
• Here it becomes oxidised and results in proliferation of LDL on the smooth muscle resulting in unfavourable changes
• Narrowing of artery

High Density Lipoprotein (HDL)
• So called ‘good’ cholesterol to protect against heart disease.
• HDL act as the scavenger in the reverse transport of cholesterol – removing from arterial wall and transporting to the liver.

Question 29

Functions of Fat

Answer 29

Fats have many functions in our body:
• Part of cell membranes and component of many body
compounds.
• Body fat protects internal organs.
• Provides insulation from heat loss.
• Source of fat-soluble vitamins and essential fatty acids.
• Concentrated source of stored energy.