Fat: Types, Sources, Importance, Functions, Risks

Fat and it's Importance in Human Body

Fat is one of the three macronutrients along with carbohydrates and protein. We get heat and energy from fat. Fat is made up of carbon, hydrogen, and oxygen like carbohydrates while oxygen is in a lesser amount than carbohydrates.

The term oil, fat, and lipid are often confused. Oil has a short or unsaturated fatty acid chain and liquid at room temperature while fats are solid at room temperature lipids are not necessarily a triglyceride.

Fats are hydrophobic in nature i.e. soluble in organic solvents but insoluble in water. Fat is the richest source of energy, one gram of fat after oxidation produces 9.0 Kcal of energy. Fatty acids are the basic unit of fat. There are almost 100 types of fatty acids available. 

Fatty Acid

Fatty acids are of two types - 

1. Saturated Fatty Acids

This type of fatty acids have carbons linked with single bonds. 
Example - Palmitic acid, Stearic acid, etc.

2. Unsaturated Fatty Acids

Contains double bonds. Example - Oleic acid, Linoleic acid, etc. Unsaturated fatty acids are again divided into two categories which are - 

A. MUFA or Mono Unsaturated Fatty Acid
B. PUFA or Poly Unsaturated Fatty Acid

Essential Fatty Acids or EFA

Fatty acids that couldn't get produced inside our body so we need to take them through our foods are known as Essential Fatty Acids. Example -
A. Linoleic Fatty Acid - Found in a huge amount in sunflower and cottonseed oil, rice bran oil, soybean oil. Besides, there are oils from nuts and seeds which contain linoleic fatty acid in a small quantity.
B. a-Linolenic Fatty Acid - Rich sources are wheat, bajra, soybean, green vegetables, black gram, mustard oil and seed, fenugreek, flax seeds, etc. Fish oil also contains enough amount of linolenic fatty acid.

C. Arachidonic Acid - Rich sources are meat, eggs, fishes, seafood, milk, and milk products.

Amount of EFA in various food

  1. Sunflower oil, sesame oil, black sesame seeds, soybean oil, flaxseed oil - 40 to 78%
  2. rapeseed, rice bran oil, peanut oil - 29 to 32%
  3. Egg yolk, poultry fat, lard - 15 to 22%
  4. Coconut oil, butter, ghee, beef, goat meat, vanaspati - 3 to 5%

Sources of Fat

  1. Pure oil, Fat, Ghee, and Vanaspati - 100%
  2. Butter - 80-81%
  3. Nuts and Oilseeds - 40-60%
  4. Powdered milk (with fat) - 26%
  5. Eggs - 14%
  6. Meat and Fish - 10-15%
  7. Cow milk - 4%
  8. Buffalo milk - 7%
  9. Lentils (unbroken) - 3-5%
  10. Cereals and Millet - 2-3%

How much fat do we need daily?

According to DRI(Dietary Reference Intake), 20% - 35% of calorie intake should be from fat for an adult. If we are consuming 2000 calories per day, there should be 44 to 77 g of fats.
Actually, it depends on many factors like height, weight, age, gender, physical condition, daily routine, food habits, etc. This calculator can be helpful to access the amount of fat a human being should have.

Types of Fat

Fats can be divided into some categories. Such as - 

1. According to Visibility:

A. Visible Fat - Fat that we include in our foods like butter, ghee, various oils, etc. are called visible fats.

B. Invisible Fat - Fat that we take through our food invisibly are known as invisible fats. Such as when we are eating a boiled egg, we invisibly consume almost 11 grams of fat.

2. According to Physical State:

A. Solid Fat - Fat that remains solid at room temperature. Example - Vanaspati, Margarine, etc.

B. Liquid Fat - Fat that remains liquid at room temperature. Such as oil.

3. According to Source:

A. Vegetable Fat - These are mainly oils we get from various seeds such as mustard oil, coconut oil, sesame seed oil, etc.

Characteristics of fat we get from vegetables:

  • Remains in liquid form. Exceptional - Margarine and Vanaspati.
  • All essential fatty acids(EFA) are available in enough quantity. Vegetable oils are beneficial for the growth of children and a growing fetus.
  • Full of unsaturated fatty acids except for coconut oil and palm oil.
  • Vegetable oils do not contain vitamins A and D.
  • The presence of vitamin E increases the self-life of vegetable oils by its anti-oxidation power.
  • They don't increase the level of cholesterol in the blood except for vanaspati.

B. Animal Fat - Fats we get from animals such as ghee, butter, fish oils, etc.

Characteristics of Animal Fat:

  • It is a triglyceride.
  • Stays solid at room temperature.
  • Animal fat lacks some essential fatty acids except for fish oil.
  • Rich source of saturated fatty acids.
  • Vitamin A and D are available.
  • It cannot be preserved for a longer time as it doesn't have vitamin E.
  • Increases the level of cholesterol in the blood.

4. According to Structure: 

A. Simple Fat - A simple fat molecule is consists of three fatty acids and one glycerol. It doesn't contain any other substance other than fat. It is a triglyceride in nature.

B. Compound Fat - Here fat is found in a mixture with one or more organic or inorganic compounds or with both. Such as - 
  • Fat + Carbohydrates = Glycolipid
  • Fat + Protein = Lipoprotein
  • Fat + Phosphoric Acid + Nitrogen Base = Phospholipid
  • Fat + Sulphuric Acid = Salpholipid

C. Derived Fat - Fat that we get after hydrolyzing simple and compound fats are known as derived fat. Such as - Fatty acids, alcohol carotenoids, glycerol, fat-soluble vitamins, etc.

Functions of Fat in the Human Body:

  1. Provide Energy: Fat or lipids are the second important source of heat and energy after carbohydrates. 1 gram of fat provides 9 Kcal energy.
  2. Water insolubility helps the fat to be stored inside the body as a future energy source. 
  3. Vitamin Absorption: Helps in the absorption and transportation of vitamin A, D, E, and K in our body. These vitamins are soluble in fat so without fat, they fail to get absorbed into the body.
  4. Essential fatty acids save us from various skin diseases.
  5. Protect Body: Adipose tissues create a thick layer around the kidney and other soft internal organs of the human body to protect them from any external hits.
  6. Cholesterol helps to produce vitamin D and hormones named Estrogen and Progesterone.
  7. Maintain Body Temperature: The layer of fat present underneath the skin helps to insulate the body. It is actually adipocytes that act as a cushion in the hypodermis and hold the temperature.
  8. Fat Storage for Subsequent Use: If we consume more energy than the body needs to perform its normal functions, then the excess food is stored as subcutaneous fat under the skin.
  9. Fat takes a long time for digestion which gives us a feeling of fullness for a longer time.
  10. The presence of fat makes food delicious by enhancing its taste and smell.
  11. Fat helps to make skin smoother and glowing.

Health Risks of Fat

The presence of fat satisfies our taste buds but excessive consumption can lead us to the danger of having various diseases.
  1. Obesity: Extreme consumption of fat leads to gain too much bodyweight which affects the overall health situation badly.
  2. Risks of Heart Diseases: Overweight creates high blood pressure along with a high risk of atherosclerosis which causes artery blockage and stroke.
  3. Diabetes: Fat hampers the balance of insulin hormone in our body leading to diabetes which further leads to heart diseases.
  4. Secretion of male hormones in women gets increased because of excessive fat consumption which not only causes heart disease but also creates male signs like baldness, facial hair growth, etc.
  5. Sleep Disorders: Overweight invokes sleeping disorder. The worst part is sleep apnea where a person stops breathing several times while sleeping at night and it can cause stroke and other heart diseases.


So this was all for today guys. If you are following my blog you would know that the other two macronutrients(carbohydrates and protein) have been discussed earlier. 

I hope this Nutrition Series is helping you guys to refurbish your daily food habits and lifestyle. Let me know your opinion through the comment section below.

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Thank you for visiting and reading.
Love and care from Anny's Pen.
See you in the next blog.

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  1. Nice one Anny!
    Everyone needs to get this new knowledge!