Fats are one of the important components of the diet. Fat is a concentrated source of energy and gives more than twice the amount of energy when compared to proteins and carbohydrates.[Carbohydrates and proteins give 4 Kcal / gram whereas fats provide 9 Kcal /gram]
Technically speaking they are a group of compounds that are soluble in organic solvents and insoluble in water. Chemically, they are the triesters of glycerol and fatty acids.
Fats can be solid or liquid at room temperature. If a fat is liquid at room temperature it is called oil and those that are solid at room temperature are called fats.
Lipid is a term that is used to denote both fats and oils. Sometimes these words are used interchangeably though.
Fats in the diet are of two types
1. Visible fat – Those derived from animal sources like butter, ghee etc and from plant sources like groundnut oil, coconut oil, sesame seed oil, safflower oil etc.They are also known as added fats.
2. Invisible fats-Apart from the added fats,certain amount of fat is present in the food stuff itself. Every food stuff right from cereals to pulses to milk meat and eggs have invisible fats.
Sometimes invisible fats play an important role in determining the effectiveness of a diet.If a diet is high in nuts,oilseeds,animal foods,avocado,soyabean etc,it had more invisible fat and a senseless planning will surely wreck havoc.
Fats can also be classified as
1. Edible animal fat – Butter ,ghee,lard[pig fat],fish oils etc
2. Edible vegetable fats – Groundnut oil, sesame seed oil, sunflower oil ,olive oil and other vegetable oils.
Another major classification that is very important to us clinically is based on their structure
1. Saturated fats - Diets high in saturated fats are related to rise in risk of cardio vascular diseases[related to heart].
Some of the examples of foods having saturated fats are dairy foods – cream ,cheese , butter, ghee and animal fats like suet, tallow, lard, fatty meat, cotton seed oil, chocolate and some processed foods.
2. Unsaturated fats – There are several sub divisions under this category like
a) Mono unsaturated fats
b) Poly unsaturated fats
c) Trans fats
Mono unsaturated fats or MUFA are liquids at room temperature and semi solid / solid when stored in a refrigerator .It is found in nuts, avocados, olive oil, groundnut oil, sesame oil,corn oil, sunflower oil, safflower oil ,pop corn, etc.
Poly unsaturated fats or PUFA remain as liquids at room temperature and in the refrigerator. They easily combine with oxygen and become rancid. They can be seen in fish, cereals-whole grain wheat, peanut butter, margarine, bananas, hemp seed and sunflower seeds.
Trans fats can be MUFA or PUFA. Small amounts of trans fats are found in meat and diary foods but is found to a larger extent in deep fried foods and industrially processed foods.
So now are you not eager to know which fats are good and which are likely to cause health problem? This and a lot more of interesting stuff coming right up..So, stay tuned…
Labels: Nutrients demystified