Fats are the most important lipids found in nature. They are one of the three majors “food factors” needed for human body, the other two being proteins and carbohydrates. Fats are widely distributed in foods and are of great nutritional value. They provide a concentrated energy store in the animal’s body to maintain optimal body temperature. One gram of metabolized fat gives 9 kcal, while the corresponding values for carbohydrates and proteins are 4 kcal and 5.5 kcal, respectively.
Not only the edible fats occupy a place of pride in human diet but they also find use as raw material for the manufacture of soaps and synthetic detergents, paints and varnishes, polishes, glycerol, lubricants, drying oils cosmetics, printing inks, linoleum oil cloth and pharmaceuticals
Fats are a class of chemical amalgam that contains fatty acids. Energy is reserved in the body largely in the form of fat. It is required in the diet to provide essential fatty acids. Fat is an important part of a healthy diet but it has some bad impacts too.

Saturated Fatty Acids Vs Unsaturated Fatty Acids

Saturated fatty acids are the simplest form of fat, a non-branched linear chain of CH2 groups connected to a terminal carboxylic acid by a single carbon-carbon bond. In contrast, unsaturated fatty acids are more complex fatty acids with curved hydrocarbon chains connected by carbon-carbon double bonds with terminal carboxylic acid groups.

Now, we will discuss briefly about Unsaturated Fatty Acids.
As discussed before, Unsaturated fatty acids contain one or more double bonds and therefore can absorb additional hydrogen atoms. Unsaturated fatty acids are two types:

1. Monounsaturated fatty acid

It consists of one double bond. Monounsaturated fats are good fats. It is known as omega-9 fatty acids.

Omega-9 Fatty Acid

Omega-9 fatty acids are monounsaturated, meaning that they have only one double bond. Nine carbons are separated from the omega end of the fatty acid molecule. Oleic acid is the most common dietary omega-9 fatty acid and the most common monounsaturated fatty acid. Omega-9 fatty acids are not strictly “essential”. That is, it can be produced in the body. In fact, omega-9 fat is the most abundant fat found in most cells in the body. However, eating foods rich in omega-9 fatty acids instead of other types of fat can have many beneficial health benefits. Large studies have shown that in diabetic patients, eating a diet high in monosaturated fat reduces plasma triglycerides by 19% and “bad” very low-density lipoprotein (VLDL) cholesterol by 22%. understood.
Another study found that feeding mice a diet high in unsaturated fats improved insulin sensitivity and reduced inflammation. The same study found that people who ate a high-saturated fat diet had less inflammation and were more sensitive to insulin than those who ate a high-saturated fat diet.

Sources Of Omega-9 Fatty Acid

Sunflower oil, Almonds, Olives, Peanut, Cucumber etc.

Good Impact Of Omega-9 Fatty Acid

1. Equivalence of the cholesterol level in the blood
2. Keep the heart-healthy
3. Reduces the risk of cancer
4. Expand the HDL
5. Diminish Inflammation

2. Polyunsaturated fatty acid

It consists of more than one double bond. They are of 2 types; Omega-3 and omega-6 fatty acids.

a. Omega-3 Fatty Acid

Omega 3 fatty acids are polyunsaturated fats and are a type of fat that the body cannot produce on its own. “Omega 3” refers to the location of the last double bond in the chemical structure. This is the “omega” or the three carbons from the end of the molecular chain.
As the human body cannot produce omega 3 fatty acids, these facts are called “essential fats” and must be taken from the diet. The three most common omega 3 fatty acids are:

1. Eicosatetraenoic acid (EPA): The main function of this 20-carbon fatty acid is to produce a chemical called eicosanoids that helps control inflammation. EPAs also help reduce the symptoms of depression
2. Docosahexaenoic acid (DHA): DHA, a 22-carbon fatty acid, accounts for about 8% of the weight of the brain and is very important for normal brain development and function.
3. α-linolenic acid (ALA): This 18-carbon fatty acid can be converted to EPA and DHA, but the process is not very efficient. ALA is mainly used by the body for energy. Omega 3 fat is an important component of human cell membranes.

They also have several other important functions, including:

Improving Heart Health: Omega 3 Fatty Acids Can Increase “Good” HDL Cholesterol. It can also reduce triglycerides, blood pressure and the formation of arterial plaques.
Mental Health Support: Ingestion of omega 3 fatty acids may reduce symptoms of depression, schizophrenia, and bipolar disorder. It may also reduce the risk of psychotic disorders in individuals at risk.
Weight and Waist Reduction: Omega 3 fat plays an important role in weight management and helps reduce waist size.
Reducing Liver Fat: Including omega 3 fatty acids in your diet helps reduce the amount of liver fat.
Supporting Infant Brain Development: Omega 3 fatty acids are very important for infant brain development.
Fighting Inflammation: Omega 3 fat has anti-inflammatory properties. That is, it reduces inflammation in the body and can cause some chronic illnesses.
Prevention of dementia: People who eat a lot of fish rich in omega 3 fatty acids tend to slow down their brain function with age. Omega 3 fatty acids may also help improve memory in the elderly.
Asthma Prevention: Taking omega 3 fatty acids can help reduce asthma symptoms, especially at a young age.

Sources

1. Fish
2. Vegetables.

Good impacts of Omega-3 Fatty Acids 

1. Improving heart health
2. Reducing fat & waist size
3. Treatment of diabetes mellitus
4. Preventing Asthma
5. Supporting mental health

b. Omega-6 Fatty Acid

Like omega3 fatty acids, omega6 fatty acids are polyunsaturated fatty acids. The only difference is that the final double bond is six carbons from the omega end of the fatty acid molecule.
These fats are mainly used for energy. The most common omega6 fat is linoleic acid, which can be converted to longer omega-6 fats like arachidonic acid (ARA).
The recommended ratio of omega-6 fatty acids to omega-3 fatty acids in the diet is 4:1 or less. However, the Western diet has a ratio of 10:1 to 50:1.
Some omega-6 fatty acids have shown benefit in treating symptoms of chronic diseases. Gamma linolenic acid (GLA) is an omega-6 fatty acid found in certain oils, such as evening primrose oil and borage oil. When consumed, most of it is converted to another fatty acid called dihomo gamma linolenic acid (DGLA).
One study found that taking high doses of GLA supplements significantly reduced some symptoms of rheumatoid arthritis. Another interesting study found that taking GLA supplements along with breast cancer drugs was more effective at treating breast cancer than the drugs alone.
Conjugated linoleic acid (CLA) is another form of omega-6 fatty acid that has several health benefits. For example, one large study found that supplementing with 3.2 grams of CLA per day was effective in reducing body fat in men. Omega-6 fatty acids are essential fatty acids that are an important source of energy for the body.

Sources

1.Walnuts
2. Sunflower seeds
3. Soybeans
4. Sunflower oil
5. Corn oil etc.

Good impacts of Omega-6 Fatty Acid

1. Reduce the symptoms of eczema
2. Decrease the formation of blood clots
3. Brain development
4. Regulation of metabolism

Bad impacts of Omega-6 Fatty Acid

1. Increase Pain
2. Depresses brain function

Trans Fatty Acid

Trans fats, or trans fatty acids, are a type of unsaturated fatty acid. They are provided in both natural and artificial forms. The most well-known trans fat in ruminants is conjugated linoleic acid (CLA) in milk fat. These are considered beneficial and are sold as dietary supplements. However, artificial trans fats, also known as industrial trans fats or partially hydrogenated fats, are harmful to health.
There are two forms of trans fat.

1. Natural, which occur in some animal products and aren’t considered harmful, and
2. Artificial, which are hydrogenated vegetable oils and have serious health consequences.

They have several effects on the human body, including:

1. Trans fats can significantly increase the risk of heart disease.
2. Trans fats can promote insulin resistance and type 2 diabetes, but the results of human studies are mixed.
3. Studies show that trans fats increase inflammation, especially in overweight and obese people.
4. Trans fats can damage the inner layers of blood vessels. However, their impact on cancer risk is less clear.
5. Processed foods containing partially hydrogenated vegetable oils are the most abundant source of trans fat in modern diets, although regulatory agencies have recently begun to limit them.

Sources

1. French fries
2. Chicken fries
3. Stick margarine
4. Packaged snack foods etc.

Cis Fatty Acid

Cis fat belongs to unsaturated fats which provide good fat to the body. Cis fatty acids have both hydrogen atoms located on the same side. Fatty acids with a cis configuration are characteristic of natural foods.

Sources

1. Olives
2. Avocados
3. Olive oil
4. Canola
5. Nuts etc.

Impacts of Cis Fatty Acid

1. Decrease the risk of heart disease and stroke
2. Expand the HDL level
3. Balance the blood pressure
4. Prevent the abnormal heart rhythms

The consensus between dietitians, nutritionists, and other experts is that Omega 3, 6, 9, and Cis Fatty Acids is more healthful than Trans Fatty Acids. However, the overall health impact remains controversial. Some researchers believe that excessive amount of any fat may increase the risk of heart disease, while others believe moderate amounts might benefit overall health