Diet 2 Flashcards
Diet
Food taken into mouth
nutrition
utilisation of food to enable the body to build, maintain and repair body tissue. Also, to supply heat and energy for the body
Essentials of the diet
- carbohydrates
- proteins
- fats
- vitamins
- mineral salts
- water
- fibre (roughage)
Eatwell plate
- fruit and veg - 5 a day
- starchy food (bread, rice, potatoes etc) - go for wholemeal = fuller for longer
- milk and dairy products (milk, cheese, yoghurt etc) choose low fat, smaller portion, full fat less frequently
- protein (meat, fish, eggs, beans etc) contain many vitamins and minerals
- sugar and fat - have small amounts of - sugar = tooth decay
15g per 100g = high
<5g per 100g = low
Water/H2O
- drink plenty = prevents dehydration
- 6-8 glasses daily
- 70% of body weight
- 3 litres required daily (2 drunk, 1 in food)
Some functions:
- dilutes and moistens food
- transports substances
- helps formation of urine and faeces
- gives moist environment from body cells
Salt
- adults = no more than 6g daily
- 75% of salt already in food we buy (cereals, soups, sauces etc)
Roughage
- indigestible part of diet
- source = cellulose part of fruit and veg etc
- function - gives bulk to diet, stimulates bowel movement
Carbohydrates
- provide heat and energy if you eat more than your body needs its converted to fat and stored
- made up of various sugar ‘building blocks’ - saccharides
What are the types of carbohydrates
- monosaccharides
- disaccharides
- polysaccharides
Monosaccharides
- simplest form of- composed of single units
- carbohydrates absorbed from gut as monosaccharides - more complex carbohydrates broken down
- e.g. glucose, fructose and galactose
Disaccharides
- 2 monosaccharide molecules joined together chemically
- e.g. sucrose, maltose, lactose
Polysaccharides
- many monosaccharides joined
- e.g. starch, glucose and cellulose
Mono- and disaccharides are more readily converted to acids
Fats
- consist of carbon, hydrogen and oxygen
- two groups: animal and vegetable
- animal sources - milk, cheese, butter, eggs etc
- vegetable sources - margarine, vegetable oils, nuts
- for absorption fats broken down to fatty acids and glycerol
- function - produce heat and energy, support certain organs, transport fat soluble vitamins
Proteins
- made up of units chemically linked (amino acids)
- each protein has specific number of amino acids
- Before absorption, proteins must be broken down
into constituent amino acids composed of carbon,
hydrogen, oxygen, nitrogen, sulphur, phosphorus
Functions: - growth and repair of body cells
- synthesis of enzymes
- plasma proteins
- antibodies
Complete (first class) proteins
- contain all essential amino acids to maintain health
- sources - meat, milk, fish, eggs, milk products (except butter) etc
Incomplete (second class) proteins
- do not contain all amino acids
- sources - mainly vegetable in origin, also cereals and pulses (peas, beans, lentils)
What are the mineral salts
- calcium
- iron
- phosphorus
- iodine
- sodium
- potassium
Inorganic compounds required in small quantities
Calcium
- source - milk, cheese, eggs, green veg
- function - haemostasis
- formations of bones and teeth
Iron
- source - liver, kidney, beef, egg yolk, green veg etc
- function formation of haemoglobin
Phosphorus
- source - cheese, liver, kidney, oatmeal
- function - associated with bone and tooth formation
Iodine
- source - salt water fish, some veg
- function - essential for thyroid gland secretions
Sodium
- source - fish, meat, eggs, milk, table salt
- function - maintenance of body fluid balance, contraction of muscles, transmission of nerve impulses
Potassium
- source - widely distributed in all foods
- function - similar to sodium
Vitamins
Two groups:
- fat soluble - A, D, E, K
- water soluble - B complex and C
Vitamin A - Retinol
- source - fish, liver, oil, eggs, milk, green veg, carrots etc
- function - needed for growth, maintenance of epithelium, vision in dim light
- deficiency - changes in epithelium, night blindness
Vitamin D
- source - eggs, butter, fish oils, milk, liver, margarine
It can be synthesised within body by sunlight on skin - function - formation of healthy bones
- deficiency - rare - rickets, delayed tooth eruption
Vitamin E
- source - vegetable oils, eggs, butter, wholemeal, cereals
- human deficiency unlikely
Vitamin K
- source - fish, liver, leafy green veg, fruit
- function - formation of prothrombin, also other factors in blood clotting
- deficiency - excessive bleeding
B complex
B1 - Thiamin
B2 - Riboflavin
B6 - Pyridoxine
B12 - Cyanocobalamin
- sources - seeds, milk, liver etc
- deficiency - digestive complaints, anaemia, skin lesion, gingival bleeding, glossitis
- folic acid - found in liver, kidney, leafy vegetables. Essential for maturation of erythrocytes.
Vitamin C - ascorbic acid
- source - citrus fruit, some vegetables e.g. potatoes
- function - formation of collagen
- deficiency - gingival and periodontal problems,
scurvy - rare, skin lesions
