Food and Nutrition Revision (AQA)

Growth, repair and secondary source of energy

Excess protein --> glucose --> glycogen in liver

Amino acids- 22 known, 10 indispensible for children, 8 for adults

Animal- all indispensible amino acids (IAAs)- high biological value proteins (HBV)

Vegetable- lack one or more IAAs- low biological value proteins (LBV)

Complementation of proteins- mix and match, e.g. peanut butter sandwich- gives variety of amino acids- vegetarians get all AAs by eating different veg protein foods together

Novel proteins- microorganisms --> mycoproteins (Quorn)- chunks/mince- low fat, no cholesterol, vegetarian protein source

Adults: Females- 45g per day, Males- 55g per day

Pregnancy- 51g, Breastfeeding- 56g

Deficiency = retarded growth in children, wasting muscles and internal organs

Provision of energy- cheapest source

Carbs --> glucose --> bloodstream for energy --> excess in liver as glycogen

Protein sparing- eating with proteins so they proteins used for growth and repair instead of energy (more expensive)

50% of total energy intake, up to 11% from sugars

Excess stored as body fat (if not glycogen)

Intrinsic sugars- cell structure of plants- fructose (fruit), glucose (fruit and veg), galactose (part of lactose), lactose (milk)- fruit, onions, beetroot, tomatoes, milk

Extrinsic sugars- added for sweetness and quick energy- sucrose and honeycomb- no other nutritional value- golden syrup, caster sugar etc.

Starch- photosynthesis in plants- longer to digest i.e. slow releasing carbohydrates- cereals, bread, root veg, pulses, bananas, rice, pasta

 NSP/dietary fibre- cellulose and pectin- movement of waste in large intestine- control blood sugar levels (less snacking)- low in fat and contain vits and mins- pulses, wholemeal bread, wholegrain cereals, wholeweat pasta, brown rice, skin on baked potato, dried fruits, veg