You always hear the message “Eat less fat” from doctors, nutritionists, and everyone else. You should avoid fats in your diet. But the truth is that we cannot live without fats and not all fats are bad for our health.
Fat is also an essential component in nutrition like carbohydrates and proteins. Our bodies need small amounts of good fats for proper function and to prevent a lot of diseases.
Fat acts as an energy reserve in the body during times of physical activity. Therefore, they are also an important part of our diet. So, let’s understand about fats and their types, functions, sources, examples, etc.
What are Fats in Nutrition?
Definition: Fats are esters of fatty acids with glycerol and a mixture of lipids. A fat is oily, an organic compound that is made up of three molecules such as carbon, hydrogen, and oxygen atoms joined together.
The number of carbon and hydrogen atom in fat is more and the number of oxygen is less. The general formula for fat is C57H110O8. Fat insoluble in water but dissolves in oil (petrol), ether, chloroform, and carbon tetrachloride.
Fats are an essential part of our diet which on average an adult needs about 75-100 grams of fats and it is important for good health.
1 gram of fat provides 9.3 kilocalories on complete combustion which is about 2.25 times more than the energy provided by the same amount of glucose.
Types/Classification of Fats
Fats can be classified into three categories. They are as follows:
On the basis of Fatty Acids: Fats are divided into two parts on the basis of fatty acids that occurred in it.
- Saturated Fatty Acids
- Unsaturated Fatty Acids
Saturated Fatty Acids
If fats have no double bond between the carbons of the molecular chain, they are called saturated fats. In saturated fatty acids, the number of carbons is equal to number of hydrogen atoms. Only simple bonds occur in saturated fatty acids.
Examples of saturated fatty acids are palmitic acid and stearic acid. Saturated fatty acids occur in desi ghee, vanaspati ghee, and butter. If you eat a greater amount of saturated fats in your diet, it will increase the risk of heart disease and high blood cholesterol levels. Therefore, they are called bad fats.
These fats are generally solid at room temperature. These saturated fats are also called lipids. Saturated fats are unhealthy.
Source of Saturated Fatty Acids
Saturated fatty acids are found in both animal and plant foods.
- Animal-based product: Meat, Chicken skin.
- Plant-based product: Palm oil, Coconut, Coconut milk, and cream.
- Dairy foods: Butter, Cream, Milk, and Cheese.
- Packaged foods: Potato chips, Hot chips, Pizza, Cakes, and Sweet biscuits.
Unsaturated Fatty Acids
If fats have one or more double bonds between carbons of the chain, they are called unsaturated fatty acids. An example of unsaturated fatty acids is oleic acid, linolenic acid, and arachidonic acid.
These fats help to reduce the risk of heart disease and lower the cholesterol level. Therefore, unsaturated fatty acids are also called good fats.
Unsaturated fatty acids is divided into two types. They are:
- Mono-unsaturated fatty acid: Monounsaturated fatty acid is found in olive oil, canola oils, some nuts such as cashews, peanuts, and almonds.
- Poly-unsaturated fatty acid: Polyunsaturated fatty acid is found in fish oil(omega -3), canola oil, soybean oil, etc.
On the basis of Chemical Composition:
Fats are divided into three types on the basis of it. They are as follows:
1. Simple Fats: About 95% of fats taken by food in our body is simple fats that occur in the form of triglycerides. A triglyceride is a glycerol molecule which contains three fatty acids attached to it. These three fatty acids can be also the same or different. For example, ghee and oil.
2. Compound Fats: In the compound fats, glycerol is attached with three fatty acids and the addition of some other type of chemical element. For example:
- Phospholipids ⇒ Glycerol + Fatty acids + Phosphoric acid
- Lipoprotein ⇒ Glycerol + Fatty acids + Protein
3. Derived Fats: The fat obtained as a result of hydrolysis and digestion is called derived fats. For example, glycerol, fatty acid, cholesterol, 7-Dehydrocholesterol.
On the basis of Sources:
Fats can be divided into two types on the basis of sources: visible and invisible fats.
1. Visible Fats: Those foods in which fats are visible clearly are called visible fats. For example, ghee, butter, oil, etc. These are called pure fats.
2. Invisible Fats: In some foods, fats are not visible clearly. These are called invisible fats. For example, meat, fish, egg, paneer, grains, dry fruits, and coconut, etc.
3. Vegetable Fats: Those fats obtained from plants and trees are called vegetable fats. Sources of vegetable fats are dry fruits, coconut, soybean, linseed, mustard, etc.
4. Animal Fats: Fats obtained from animals are called animal fats. Sources of animal fats are milk, butter, ghee, egg, and meat, etc.
Functions of Fats in body
Following are the important functions of fats in our body. They are as:
1. Provides energy reserves: Fats reserve energy in the body. One gram of fat provides nine calories of energy. Fat is stored in the body in the form of adepts and can provide energy to the body on need.
2. Providing essential fatty acids: Fats provide essential fatty acids that help to maintain skin and body healthy.
3. Providing fat-soluble vitamins: Vitamin A, D, E, and K are soluble in fat. It is required for their absorption, convection, and utilization.
4. Giving protection to sensitive organs of body: There are layers of fat around soft parts of the body such as the heart, kidney, lungs, etc which protect them from the outer push and provide stability.
5. Making food tasty: Fats makes food tasty. Oily food is tastier than boiled food.
6. To provide satiety value: Fatty food is digested late due to be heavy, due to which there is no hunger.
7. Protein saving: When there is a lack of fat in the body, the energy requirement is not fulfilled with carbohydrates. In this case, protein has to work to give energy to the body leaving its own work. Thus, fats help to save protein in the body.
8. To act as lubricant: Fat provides smoothness to your skin and various organs of the digestive system such as the stomach and intestinal tract.
How many grams of fats do we need per day?
How many grams of fats should you take in your daily diet? It depends on your total daily calories. The Institute of Medicine of the National Academies recommends that 15 to 20 percent of your daily calories should come from fats.
That is, if you need 2000 calories per day, you should get 15 to 20 percent calories from fats because 1 gram of fat contains 9 calories of energy.
The recommended daily allowance of fat for 1500 calories and 2500 calories diets is 25 to 33 grams and 41 to 55 grams, respectively.
The recommended daily allowance of fats for a woman is 40 to 50 grams per day, whereas for men is 50 to 60 grams per day. 5 to 10 years old children need 30 grams of fats daily.
Effects of Deficiency of Fats
- There is a decrease in body weight.
- Lack of soluble vitamins (A, D, E, K) appears due to fat reduction.
- If protein starts to give energy to the body, symptoms of lack of protein start to appear.
- There is an effect of the digestive system and become constipation.
- Physical growth is stopped.
- Due to the lack of essential fatty acids, illnesses such as dermatitis, phrynoderma start in the skin.
Benefits of Fats in body
There are the following benefits or advantages of fats in our body. They are as:
1. Fats are essential for the proper functioning of the body. They provide essential fatty acids that are not made by the body. We get these fatty acids through the foods.
2, We need linoleic (or Omega-6) and alpha-linolenic (or Omega-3) fatty acids which are essential for controlling the swelling, clotting of blood, and development of the brain.
3. Fat also serves to store extra calories in the body and it is also important for providing a good source of energy.
4. Fats help to keep healthy our hair and skin.
5. Fats help to absorb Vitamin A, Vitamin D, Vitamin E, and Vitamin from our blood and also help in their blood circulation properly.
Side effects of Excess of Fats
1. When you will eat food having too much fats, will increase the risk of heart disease and level of cholesterol.
2. Too much eating fats increases the amounts of calories in our body due to which we may also have the problems of obesity, heart stroke, hypertension, diabetes, etc.
3. The consumption of high amounts of polyunsaturated fats also leads to some type of risk, but if you take fewer amounts of fats in your daily diet, they reduce the risk of serious diseases to be like heart disease and cancer.
4. Excess fat reduces the secretion of digestive juices, causing digestive disorders. For example: Indigestion, gas, etc.
5. Excess use of fats in the body become acidosis from which the quantity of acid increases.
What is Trans Fat?
When healthy fats such as soybean oil or olive oil go through a chemical process called partial hydrogenation, the number of hydrogen atoms add to the oil, and trans fats are produced.
Trans fats damage to the function of the cell membranes and increase the insulin levels in the blood as well as also increase the level of cholesterol. They also weaken the immune system.
What is cholesterol?
Cholesterol is a fatty substance or lipid. It is also a sterol from which steroid hormones are formed. Cholesterol flows through our bloodstream but it will not dissolve into the bloodstream.
Cholesterol plays an important role to maintain the certain body functions. It can also pose serious health diseases if it damages blood vessels.
Everyone needs a certain amount of cholesterol in order to survive because cholesterol plays an important role in hormone production.
But a person who has high cholesterol often has health problems that can contribute to the development of many serious diseases like heart disease, obesity, diabetes, high blood pressure, etc. The main cause of high cholesterol in your body is to take high-fat diets.
Your blood cholesterol level is determined by the sum of how much cholesterol your body makes and how much you take from food, minus how much your body uses up.
In this tutorial, we have covered all important points related to the definition of fat and its types, sources, functions. Hope that you will have understood the basic things and enjoyed this tutorial.
Thanks for reading!!!
