Evaluating Nutrition information and macronutrients Flashcards Preview

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Flashcards in Evaluating Nutrition information and macronutrients Deck (41)
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What is food made up of?

1. Macronutrients and alcohol (energy yielding nutrients and alcohol) 2. Micronutrients (vitamins and mineral) 3. Phytochemicals (Secondary plant metabolites -phenolic acids, flavonoids in particular carotenoids and photos ternies) 4. Water( main component of body fluids) 5. Other (preservatives, colours)


Which Components of Food  Provide ‘Energy’?


• Carbohydrates, fats and proteins are the only nutrients in foods that provide energy. Alcohol also provides energy

• These nutrients are also referred to as macronutrients and can be digested and metabolised by the body into fuel that our body uses to support physical activity and basic functioning.

• Alcohol in beverages will also provide energy/fuel for the body, however, it is not a nutrient (it is classified as a narcotic drug) because it does not support body functions.

• Although vitamins, mineral and other compounds in food are beneficial to the body in many other ways they will not provide you with the energy.



What are carbohydrates?

• Most important source of food energy in the world

• Carbs provide 17kJ/gram

• Plants make carbs from sunlight

• We eat plants and use this energy stored in the plants

• Largest single source of energy in diet

• Carbs necessary for brain function

• Many unrefined carbs provide fibre • What are the food sources of carbs???



What are carbohydrates?

Carbohydrates are chains of molecules found in three forms: 


How are carbohydrates digested?

• Begins in the mouth with salivary amylase

• Primary site of CHO digestion is small intestine where enzymes amylase, sucrase and lactase cleave disaccharides into single sugars

• Monosaccharides absorbed into bloodstream via wall of small intestine



What is dietary fibre?

• Indigestible forms of carbohydrate - not broken down to glucose.

• Fibre uses intestinal bacteria to produce energy (8kJ/g)

• Two types: soluble & insoluble



Where is insoluble fibre found?

Leaves, roots, bran, whole grains and beans 

Seed coverings (bran, wholegrains)

Plant stems, leaves and skin 


How is insoluble fibre digested and what is its function?

Does no dissolve in water

Absorbs water through the colon bulk up stools and aids defamation 

Helps to keep you regular 



Where is soluble fibre found? 


Oats and barley 

Beans, cereals, seeds, seaweed, psyllium

Inulin, gums 


How are soluble fibres digested and what is its function?

- dissolves in water- gel-like

- resistant to digestive enzymes 

- Fermented by bacteria in the colon to form acids that provide energy (8kj/g)

- Reduces blood cholesterol by binding to bile acids 



What is polydextrose?

• man-made substance similar to soluble fibre, Iso fermented by bacteria (4kJ/g), not sweet, used as a bulking agent in carbohydrate modified products 


What is resistant starch?

 naturally occurring (e.g unripe bananas) and in commercial foods, resistant to digestion in small intestine, fermented by bacteria in colon, linked with positive gut health – area of research for microbiota and health


What is glycemic index?

• Ranks carbs on measured rise in blood glucose levels compared to a reference - Low: 0-55, Moderate: 56-69, High: 70 or more

• Limitations: complex, not consistent in categories, for carbs only



How much of our energy intake should come from carbohydrates?

45-65% total carbohydrate 

15-25% protein

20-35% total fat 



basic facts 


What is protein?

A unique macronutrient as contains nitrogen

• Dietary protein provide amino acids for body to make proteins.

• Human body makes an estimated 10,000-50,000+ unique proteins from 20 aa’s

• Many cells and structures in the body being broken down and rebuilt and
require a steady supply of protein

• Proteins functions include:
– growth and development

– building and repair of muscles, bones, organs, blood, skin, hair

– repair of damaged tissues due to illness or injury

– regulation of body fluids and hormones

– blood clotting Body Dietary

– helping the immune system fight disease protein



Function of dietary protein:

Protein is essential for many body functions including:
– growth and development
– building and repair of muscles, bones, organs, blood, skin, hair
– repair of damaged tissues due to illness or injury
– regulation of body fluids and hormones
– blood clotting
– helping the immune system fight disease



 What is the process of protein digestion and uptake?

• Begins in the stomach with denaturing of protein to expose chains -more efficient enzymes activity

• Digestion is completed in small intestine with trypsin, chymotrypsin and other enzymes.

Amino acids — go to bloodstream



What are the protein requirements of the body and what do these depend on?

Can be determined by measuring nitrogen balance Protein being used by body: = Nitrogen consumed (dietary protein)
minus nitrogen excreted (urine and faeces)

• -ve nitrogen balance: more nitrogen excreted than input;
more proteins being broken down than synthesised eg. Illness, injury, surgery, lose wt

• +ve nitrogen balance: less nitrogen lost than ingested; body is using dietary protein for synthesis of new protein

eg. Pregnancy, lactation, growing child

• Nitrogen balance: total body protein does not change



Protein requirements depend on: 

- genetic makeup 

-age, growth 

-body size, muscle and bone mass

-pregnancy and lactation 

- illness and injury 



How much of our energy intake should come from protein 

15-25% protein 



basic facts 


What are lipids?

• Lipids are insoluble in water

• Many different forms in food and in the body.  Three types
commonly found in foods and in cells and tissues of the body are:
– Triglycerides

– Phospholipids

• Triglyceride are most common food based lipid.  Named because it has a glycerol head with 3 fatty acid chains

• Fats in our food = Triglycerides with combinations of different fatty acids.  Triglycerides can be classified by their chain length, level of saturation , location of double bonds and isomeric form. 


What animals products can protein be found?

Animal protein sources, such as meat, fish, poultry, eggs and dairy, are similar to the protein found in your body. These are considered to be complete sources of proteinbecause they contain all of the essential amino acids that your body needs to function effectively.


What plants have proteins in them?

Tofu, tempeh, and edamame. Soy products such as tofu, tempeh, and edamame are among the richest sources of protein in a vegan diet. ... 

Lentils. ... 

Chickpeas. ... 

Peanuts. ... 

Almonds. ... 

Spirulina. ... 

Quinoa. ... 



What is the fats classification by carbon chain length? 

1. Short-chain fatty acid (less than 6 carbons)

2.Medium-chain Fatty Acid (6-12 carbons)

3. Long-chain Fatty Acid (12 or more carbons) 


Fats classification by saturation 

1. Saturated 

2. Unsaturated 


What are the essential fatty acids?

omega-3 and omega-6 


Which type of fat is not recommended 

Trans fats 


Describe the broad classification of dietary lipids 

Refer to image