Part of a group of compounds known as lipids and composed of the elements carbon,oxygen and hydrogen,fats are found mainly in plants,fits and meats.They form a major part of all cell membranes in the body and play a vital role in the absorbtion of the fat soluble vitamin A,D,E and K from foods.
Fat gives the body insulation,helping to maintain a constant temperature against extremes of hot and cold.It is also serves as an important source of energy.
In addition to fats,lipids include phospholipids,tryglicerides,waxes and sterols.The most known sterol is cholesterol which circulates in the blood attached to compounds known as lipoproteins.
Low density lipoproteins (LDL) which carry cholesterol in tissues and organs are often called "bad" cholesterol,since high levels in the blood are associated with an increased risk of cardiovascular disease.
High density lipoproteins (HDL),which carry cholesterol away from the tissue and back to the liver are known as "good" cholesterol,since high level decrease the risk of cardiovascular disease.
Fats are also referred to as "good" or "bad" according to whether their chemical bond are "saturated" with hydrogen.Unsaturated fats are further classified into mono and polyunsaturated,which differ in their nutritional makeup.
Avoid saturated fats
With the exception of palm and coconut oil,most saturated fats are derived from animal and dairy products.Red meat and meat products such as sausages are major sources of saturated fat in the diet,along with whole milk and its products,such as cheese,cream and ice cream.
Excessive intake of saturated fats and trans fatty acids are now belived to increase the risk of cardiovascular disease by raising the unhealthy LDL levels,so they should be restricted in the diet.
Unsaturated fats
A diet high in monounsaturated fats which are found in plant oils,avocados and nuts,helps lower levels of LDL and triglycerides in the blood,without lowering healthy HDL levels.
Polyunsaturated fats consist of two major types: omega 3 fatty acids,found in fish oils and omega 6 fatty acids,found in vegetables oils such as sunflower,rapeseed and corn.Your diet should include both types.
Trans fatty acids
These occur naturally (in small amounts) in meat and dairy products,but they are also produced during the process of hydrogenation,which is used to convert semi-solid fats in the manufacture of some types of margarine.
Trans fats are most commonly found in biscuits,cakes,pastries,meat pies,sausages,crackers and take away foods.
Although chemically trans fats are still unsaturated fat,studies show that in the body they behave like saturated fats,causing blood cholesterol level to rise.In fact some studies suggest that trans fats are worse than saturated fats.
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