1.3 nutrition and health

• the 7 main nutrients for a balanced diet are : carbohydrates, lipids, fibre, proteins, vitamins, minerals and water
• a 'balanced' diet incorporates all the nutrients in their adequate proportions
• The term malnourished means a lack of one of more essential nutrient from your diet, or you may eat excess of one or more essential nutrient.
• If one is featuring a malnourishment of vitamin c, they would experience scurvy
• if one is featuring a malnourishment of iron, they would experience anemia
• If one is featuring a malnourishment of vitamin d, they would experience rickets
• In the UK, most of the population receives enough vitamins and minerals, however our diet may lack in terms of energy intake.
• Carbohydrates contain oxygen, carbon and hydrogen.
• There are two types of carbohydrates : simple carbohydrates ( eg : glucose and lactose ) and complex carbohydrates (eg : glycogen, starch, cellulose )
• The simplest carbohydrates are the sugars. Glucose is one sugar unit and lactose is a molecule bonded with glucose and galactose.
• Sugars are small, soluble molecules
• Sugars provide a ready, rapid source of energy
• Many sugar molecules are linked to form complex carbohydrates
• Complex carbohydrates are insoluble
• Starch is a complex carbohydrate which is used in storage of plants. A starch molecule consists of thousands of glucose molecules joined together in a chain.
• Glycogen is a complex carbohydrate which is found in animals for storage. Liver cells and muscle cells contain glycogen. Storing excess glycogen is controlled by a hormone secreted by the pancreas called insulin
• Cellulose is a structural complex carbohydrate found in plants. It can be used to build cell walls. Cellulose fibres are constructed from sugar molecules linked together in long chains.
• Lipids contain oxygen, carbon and hydrogen
• There are two forms of lipids called fats and oils
• Fats are solid at room temperatures, usually from animals - butter, lard
• Oils are liquid at room temperature, usually from plants - sunflower oil, olive oil
• Fats are stored in a layer under the skin
• The layer under the skin where fats are stored acts as an energy store, insulator and protective layer
• Fats are also required for the production of cell membranes
• Lipid molecules are composed of glycerol and 3 fatty acids in the formation of the letter 'E'
• There are two types of fatty acids - saturated fatty acids and unsaturated fatty acids
• Saturated fats come from animal sources
• Unsaturated fats come from plant sources (monosaturated and polysaturated)
• Consuming too much saturated fat can lead to a build-up of cholesterol in the bloodstream
• Cholesterol is a fat-like molecule, which is made in the liver and obtained in your diet (saturated fatty sources)
• Cholesterol is required to make cell-membranes and various hormones
• Having high blood cholesterol increases the chance of developing various heart conditions and diseased blood vessels as cholesterol builds up in the walls, clogging them
• The two factors which determine if your blood cholesterol increases are the amount of foods in your diet and the way your liver functions which is inherited by genetics and cannot be changed
• Cholesterol is carried through the bloodstream by two kinds of lipoproteins (droplets containing cholesterol and protein) : LDL and HDL
• LDL means low density lipoproteins - this is the 'bad' lipoprotein and it can increase the risk of heart disease
• HDL means high density lipoproteins - this is the 'good' cholesterol and it can decrease the risk of heart disease
• a healthy artery presents a full lumen, small particles of cholesterol but an infected artery presents a narrowed lumen and large plaque consistency of cholesterol
• Proteins are composed from carbon, oxygen, hydrogen and nitrogen. Some proteins contain sulphur too.
• Proteins are built from long chains of smaller molecules called amino acids
• There are 20 types of proteins in living organisms