food and nutrition Flashcards
what are the nutrients
-carbs
-proteins
-lipids
-fibre
-water
-nutrients are the building blocks of whole foods and they have specific functions in our bodies
-we need 40 nutrients in various quantities for energy growth, maintenance and repair of body tissues
what nutrients can be classified in two groups
-macronutrients: needed in large quantities (proteins, carbs, lipids and water)
-micronutrients: needed in small quantities (vitamins and minerals)
what are the functions and sources of macronutrients = proteins
functions of proteins
-forms part of all body cells, tissues, blood, enzymes, antibodies, nails, skin, hair and hormones
-needed for growth, repair and maintenance
-supplies enemy
-one gram supplies 17 kilojoules
what are the two types of amino acids
essential: provided by food
non essential: provided by the body
what are the complete proteins
-contain all essential amino acids
-have high biological value
-are found in foods of animal origin (soya bean)
what are the incomplete proteins
lack essential amino acids
-have low biological value
-found in plant origin foods
what are plant based proteins
-legumes
-seeds and nuts
-cereal products
what are animal based proteins
-meat
-fish
-eggs
-milk and milk products
what is the protein deficiency
-deficient in protein causes stunted growth.
-oedema as a result of an imbalance of fluid in the body
what is the protein excess
-diet that contains too much protein
-risk in cardiovascular disease
-obesity
-kidney problems
what are carbohydrates
carbohydrates
monosaccharides: singular or simple sugars
disaccharides: double sugars (2 monosaccharides)
polysaccharides: large complex molecules
-starch, fibre, glycogen (glucose is stored as glycogen in the liver)
what are examples of disaccharides
-sucrose (cane sugar) = glucose + fructose
-maltose (malt sugar) = glucose + glucose
-lactose (milk sugar) = glucose + galactose
what is the function of starch and sugar
-blood carries glucose to body cells where it provides the main source of energy
-makes us fuller for longer
what are the sources of starch
found in plant based foods (bread, maize, rice)
what is starch deficiency
-lack of energy
what is starch and sugar excess
-excess carbs are converted to glycogen and stored in the liver and muscle where it’s used for body energy.
-it can be converted to fat cells
-too much sugar and result in obesity and tooth decay
what is fibre
-unbroken carbs pass through the colon where they are partially broken by the good bacteria.
what are the functions of fibre
-absorbs water, for stools
-increases the feeling of fullness
-helps to control the levels of blood glucose in diabetics
-lowers blood cholesterol levels, reducing risk of coronary heart disease
what are the sources of fibre
-fibre found in bran in cereals, legumes, seeds
what is the deficiency of fibre
-inadequate faecal bulk, which leads to constipation and even colon cancer
what is the excess of fibre
-bowel discomfort
-decrease the absorption of calcium, magnesium, phosphorus and iron