What is fat ; Fats are the concentrated sources of energy in our diet. They form an important part of our daily food. After being processed in the alimentary canal and liver, are supplied to the tissue as glycerides. Fats are also formed from glucose and amino acids. Thus carbohydrates are fattening.
Through we mainly consume fats in the form of butter, ghee, oils, etc. Some amount of fats is also present in food like milk, nuts and meat.
Types of fats :
Types of fats are following;
- Saturated fat; They are solid at room temperature. Excess eating saturated fat increases HDL cholestrol (bad cholestrol). Increases in HDL causes hypertension and heart related diseases. Which is not good for health.
- Trans fat; It make a hard form in room temperature. It is wrost fat. Trans fats thick the arteries and blood cell. What are the trans fat ? Mostly amount of trans is formed by industrial process. They provide addition of hydrogen into vegetable. These hydrogen form a solid at room temperature. Which is increase chance of heart attack. It is present in beaf, meat, etc.
- Unsaturated fat ; Unsaturated fats are liquid at room temperature. It can be easily digestible. Unsaturated fats is good for health so it is called healthy or good fat. It can be divided into two types ;
- Mono-unsaturated fat; It is not saturated with hydrogen atom. Each mono molecule bounded with one hydrogen atom.
- Polyunsaturated fat; They are also not saturated with hydrogen atom.
Functions of fat:
We will discus six major functions of fats:
- Source of energy : Fats are richest source of energy. One gram of fat gives 9 Kcal which is more than double the amount obtained from equal amounts of carbohydrates and proteins.
- Carrier of fat soluble vitamins : some fat-soluble vitamins like A,D,E and K need fat for their proper absorption and utilisation in the body. The body can suffer from deficiency of these vitamins, if enough fats are not present in diet.
- Insulation : The layer of lipid under the skin helps in maintaining body temperature.
- Protection : fats act as a cushion to important organs in body and protect them from shocks and external injuries.
- Palatability : Fats are used for cooking and frying and so make the food tasty and acceptable.
- Satiety value : They take longer time to be digested in the body. This gives us a feeling of fullness and satisfaction.
Sources of fats :
Fats are obtained from vegetable as well as animal source. What constitutes these two sources?
Vegetable cooking oils are extracted from oil seeds and nuts such as groundnut, mustard, sesame (til), soyabean, cotton seed and coconut.
Milk , egg yolk and fats like ghee, butter, cream, fish liver oils are some of the fats of animal origin.
Good or healthy fat list :
- Olive oil
- Fatty fish
- Pumpkin seeds
- Dark chocolate
- Whole eggs
- Coconuts and coconuts oil
- Full yoghurt
Daily requirement :
About 50 grams of fat are needed by man daily. It is digested slowly and delay the hunger sensation between meals. Our diet should contain less saturated fats, such as butter, ghee and hydrogenated vegetables oils. Than unsaturated fats such as simple vegetable oil. Excess the saturated fats increase the blood-cholestrol level. It may cause Arteriosclerosis (harding of arteries). Therefore these fats should be avoided by sedentary, old and obese persons and also by those suffering from heart disorder and high blood pressure.
Man should draw 10-25% of total caloric requirements from fats. Sportsmen, athletes, wrestlers, weight-lifters and manual labour, etc. May draw over 40% of their caloric need from fat. This will fulfil their high caloric requirements without increasing the bulk of food, and will keep them light.
Essential Fatty Acids :
Man can synthesised most of fatty acids his body from the fatty acid food taken. A few fatty acids are not synthesised,and must be present in the diet. They are called essential fatty acids.
They are present in unsaturated vegetables oils such as groundnut oil, sunflower oil and safflower oil. Food should contain enough essential fatty acids to supply 3-5% of the total calories.