Lipids/Fats
Fats (lipids) are a good source of calorific energy, but are so concentrated a form it is easy to unwittingly over balance your personal ‘calories consumed / calories expended’ equation with too much fat.Fats or lipids should provide the body with about 25 per cent of its calorific intake (70g for women and 90-95g for men, depending on lifestyle).
Fat is essential for the proper functioning of the body. Fats from the diet provide essential fatty acids that cannot be made in the body and must be obtained from our food.The essential fatty acids are linoleic and linoleic acid. They are important for controlling inflammation, blood clotting and brain development.Fat is also a storage substance for the body’s extra calories. Adipose tissue (fat cells) helps insulate the body.Fat is also an important energy source, when the body has used its energy in the form of carbohydrates (approximately 20 minutes of exercise) it begins to use the energy from fat.
Dietary fat exists as saturated and unsaturated fatty acids arranged in triglycerides of varying composition. Saturated and unsaturated fatty acids are both comprised of carbon, hydrogen and oxygen.A saturated fatty acid has the maximum possible number of hydrogen atoms attached to every carbon atom. It is therefore said to be ‘saturated’ with hydrogen atoms and all of the carbons are attached to each other with single bonds.In some fatty acids, a pair of hydrogen atoms in the middle of a chain is missing, creating a gap that leaves two carbon atoms connected by a double bond rather than a single bond.Because the chain has fewer hydrogen atoms, it is said to be ‘unsaturated’. A fatty acid with one double bond is called ‘monounsaturated’ because it has one gap. Fatty acids which have more than one gap are called ‘polyunsaturated’.
Saturated fats are commonly found in foods from animals. These include beef, beef fat (stearic acid), pork, cheeses and other dairy products. Saturated fats are usually solid at room temperature.Polyunsaturated and monounsaturated fats are the two unsaturated fats. They're found primarily in oils from plants.Monounsaturated fats are liquid at room temperature but may solidify when refrigerated. Food sources include olive oil, peanuts and avocados.Polyunsaturated fats are found in foods such as soybeans, corn, sesame and sunflower seeds and their oil. These fats are usually liquid at room temperature.
The diagram displays a sutarated fatty acid and an unsaturated fatty acid