Principles of nutrition

Lesson A

Unit: Applying the

principles of nutrition to a

physical activity

programme

Sam - ID 38359016

Learning outcomes & assessment criteria

Learning outcome: The learner will:

LO1: Understand the principles of nutrition.

Assessment criteria: The learner can:

1.1 Describe the structure and function of the digestive system.

1.2 Explain the meaning of key nutritional terms including: • Diet.

• Healthy eating.

• Nutrition.

• Balanced diet.

1.3 Describe the function and metabolism of: • Macronutrients.

The digestive system

Mouth

Pancreas

Liver

Gall bladder

Small intestine

Large intestine

Rectum

Anus

Oesophagus

Stomach

TASK

Research at least three:

sections of the

gastrointestinal tract or

digestive organ.

Write up your notes and

file in your portfolio.

The digestive system

TASK

Research a working

definition for each of the

following terms:

• Diet.

• Healthy eating.

• Nutrition.

• Balanced diet.

Record your findings in

your portfolio

Nutritional terminology

Sam - ID 35865083

Macronutrients Carbohydrate

• 4kcals/g.

• Energy for

nervous system

and movement.

• Made up of amino acids

joined by peptide bonds.

• 20 amino acids.

• 9 are ‘essential’ and cannot

be made by the body.

• 11 are non-essential in

healthy adults but some of

these become ‘conditionally

essential’ in certain

situations.

Protein

Sam - ID 30782981

• Animal products are

‘complete’ proteins

containing all of the

essential amino acids in

large amounts.

• Vegetable protein sources

(except soy and quinoa) are

‘incomplete’ proteins and

lack one (or more) essential

amino acid in a high

enough quantity for health.

Protein

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• Proteins make up 15-20%

of body weight.

• Structurally, proteins are an

integral component of all

cells and the fascia that

holds the body together.

• Functional proteins include

enzymes and catalysts,

haemoglobin, adenosine

(as in ATP) and peptide

hormones.

Protein

Sam - ID 30782981

• Anabolism = making bigger molecules from smaller

components, e.g. muscle tissue from amino acids.

• Catabolism = breaking down large molecules to release

components, e.g. muscle tissue to amino acids.

Protein balance

Activity type Grams of protein per

kg body weight

Sedentary adult

Recreational adult exerciser

Adult endurance athlete

Growing teenage athlete

Adult building muscle mass

Estimated upper limits (adults)

0.8g/kg

0.8-1.5g/kg

1.2-1.6g/kg

1.5-2.0g/kg

1.5-1.7g/kg

2.0g/kg

Carbohydrates

Easily broken

down for energy

release to fuel

activity.

• A scale rating how quickly a

carbohydrate-rich food increases

blood sugar.

• High glycaemic index foods

cause sharp rises in blood sugar

(glucose) and require insulin to

be released.

• Low glycaemic index foods

release sugar more slowly into

the bloodstream.

Glycaemic index

Sam - ID 779611

• Found in all plant-based foods.

• Fruits contain mostly sugar and

fibre.

• Vegetables contain mostly starch

and fibre.

• Wholegrain starchy foods are

also high in fibre.

• Refined starches have little or no

fibre and behave like sugar in the

body.

Sources of carbohydrate

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• Processed (refined)

carbohydrates and sugar are

widely over-consumed.

• This promotes obesity and type 2

diabetes.

• Carbohydrate intake is valuable

as a source of energy for

exercise and should be balanced

to match physical activity level.

• Natural sources of carbohydrate

with fibre, vitamins, minerals and

phytonutrients are generally

healthier options.

Carbohydrate and health

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Lipids

Oils

Lipids that are

liquid at room

temperature =

unsaturated.

• Most fats occur as triglycerides

made up of one glycerol

molecule that holds together

three fatty acids.

• The types of fatty acid in the

molecule determine its

characteristics.

• Triglycerides are broken down in

the gut to be absorbed into the

body then reformed in the liver

and packaged in lipoproteins

(blood cholesterol) for

transportation in blood.

Triglycerides

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Fatty acids

Saturated

• Mostly from

animal products.

• Have no

chemical double

bonds.

• Fat is over twice as energy dense

as the other macronutrients and

is easy to over-consume.

• Choosing natural sources of fat

(where it is found), alongside

protein, limits overeating.

• Processed foods where cheap

oils are added in large quantities

alongside refined starch and

sugar promote excess calorie

consumption.

Fats and health

Sam - ID 779611

Sam - ID 30782981

• Monounsaturated fats can help

lower ‘bad’ LDL cholesterol and

maintain or increase ‘good’ HDL

cholesterol levels.

• Polyunsaturated fats reduce

levels of both HDL and LDL

cholesterols.

• Saturated fats may increase both

HDL and LDL cholesterol levels.

• Trans fats increase LDL

cholesterol and suppress HDL

cholesterol.

Fats and cholesterol

ID 20371796

Learning review

LO1: Understand the principles of nutrition.

Assessment criteria: Can you now:

• Describe the structure and function of the digestive system?

• Explain the meaning of key nutritional terms including: – Diet

– Healthy eating

– Nutrition

– Balanced diet?

• Describe the function and metabolism of: – Macronutrients?