The importance of fats for humans, animals, and plants lies in their high content of energy, which permits the greatest possible storage of energy in the smallest possible amount of food substance. Fats allow humans and animals to consume fat-soluble vitamins and provide them with essential fatty acids, that is, those indispensable fatty acids that their bodies are unable to synthesize themselves.
The efficiency of fat as foodstuff is very high, because the fat contained in food is almost completely reabsorbed by the body. Fats also provide a smooth, creamy consistency to many dishes, which translates into a good mouth-feel. In addition to that, the importance of fats and oils to the global economy becomes clear when considering the amount of oilseed and fruit grown worldwide.
The importance of oils and fats for human nutrition, the animal feed produced from the processing of most oil plants and the economic importance of oils and fats, i.e., the fact that many millions of people worldwide make a living by the production and processing of oils and fats, all combine to give special importance to technology. That might even be enhanced if oil-bearing crops could be offered to the chemical industry as a source of regenerating raw materials.
Functions, Classification and Characteristics of Fats describes the role of fats in taste perception and the importance of fats in a number of food technology applications. From a nutritional point of view, dietary fats are important for several health related aspects and for optimal functioning of the human body.
Dietary fats are not just a source of energy; they function as structural building blocks of the body, carry fat-soluble vitamins, are involved in vital physiological processes in the body, and are indispensable for a number of important biological functions including growth and development. The importance of dietary fats is explained in more detail below.
Every Thing about Importance of Fats in Human Body
at is an essential part of our diet and nutrition that we cannot live without. Our bodies require small amounts of ‘good fat’ to function and help prevent diseases. However, most of our present fancied modern diets contain a lot more fat than the body requires.
Too much fat to the body can cause serious health issues like obesity, high blood pressure, high cholesterol levels etc which leads to heart disease. Like proteins, fat is also essential to human life. Fat provides a cushion to help our vital organs as without fat our organs would be prone to damage. Fat actually acts as an insulator helping us to maintain the right body temperature.
Dietary fats make food tasty as they often improve the texture of food as well as flavour and aroma – they make food more appealing. Fat enables our body to process vitamins A, D, E and K, which are all fat-soluble and vital to good health. Although we need fat, remember that we require only small quantities of the right kind of fats to stay fit and healthy.
What is FAT?
Fat is a macronutrient (like protein and carbohydrate) and is made up of fatty acids. Fatty acids can be classified as saturated or unsaturated depending on their chemical structure. Unsaturated fatty acids include monounsaturated fatty acids and polyunsaturated fatty acids. All fats provide 9 calories (kcal) per gram, which is more than double the number of calories provided by each gram of protein and carbohydrate that we eat (4 kcal per gram each). A high fat diet can therefore lead to weight gain over time.
Two Types of Fats
To understand the role fats play in a healthy diet, you have to look closer at the two types of dietary fats: saturated and unsaturated. (A third kind, trans fats, have been all but eliminated from U.S. foods.)
Saturated. This is the so-called “bad” fat. It’s primarily found in animal products like beef, pork, and high-fat dairy foods, like butter, margarine, cream, and cheese. High amounts of saturated fat also are found in many fast, processed, and baked foods like pizza, desserts, hamburgers, and cookies and pastries. These fats tend to more “solid” (think butter or lard) than healthier fats.
Unsaturated. This is the healthy kind, and there are two types: monounsaturated and polyunsaturated. Monounsaturated fats are found in avocados and peanut butter; nuts like almonds, hazelnuts, cashews, and pecans; and seeds, such as pumpkin, sesame, and sunflower seeds. It is also in plant oils, such as olive, peanut, safflower, sesame, and canola oils.
Polyunsaturated fats include omega-3 fatty acids and omega-6 fatty acids. Polyunsaturated fats are found in plant-based oils like soybean, corn, and safflower oils, and they’re abundant in walnuts, flaxseeds, sunflower seeds, and fish like salmon, mackerel, herring, tuna, and trout.
The main health issue with dietary fats is how they influence cholesterol levels. Consuming high amounts of saturated fat produces more LDL (bad) cholesterol, which can form plaque in the arteries and increase your risk of cardiovascular disease and stroke.
“Many processed and fast foods made with saturated fat also contain high amounts of calories, which can lead to weight gain and further raise your heart disease risk,” says Malik.
In comparison, the unsaturated fats help to raise HDL (good) cholesterol levels. HDL picks up excess LDL in the blood and moves it to the liver, where it is broken down and discarded. “You want to have a high HDL-to-LDL ratio, and unsaturated fats can help with this,” says Malik.
But research has found that it’s not enough just to eat more healthy fats. You also have to cut out the unhealthy saturated fat, too. A study from Harvard researchers in the March 2018 issue of The American Journal of Clinical Nutrition found that consuming monounsaturated fats, especially from nuts and olive oil, can lower a person’s risk of heart disease — especially if the healthy fat replaces saturated fat and refined carbs (which can also raise LDL levels). The researchers added that any benefit from consuming monounsaturated fats may be negated if a person continues to consume too much saturated fat.
Healthy Fat Choices
All fats are not created equal. Unsaturated fat is considered ‘healthy’ fat and saturated fat is a ‘bad’ fat. Unsaturated fats include monounsaturated and polyunsaturated. Unsaturated fats are typically liquid at room temperature.
Monounsaturated fats help lower blood cholesterol levels. Monounsaturated fats are found mainly in olive and canola oils and foods containing these ingredients, and in nuts and avocados.
Polyunsaturated fats also help lower blood cholesterol levels. Two types of polyunsaturated fats include omega 3 and omega 6 and are very important for your health. Omega 3 fats are found in fish, flax seeds, walnuts, eggs and canola oil. Good sources of omega 6 fats are seeds, safflower, sunflower, corn and soybean oils.
Saturated and Trans fat are considered ‘bad’ fats mainly because they can increase bad or LDL cholesterol levels and trans fat has also been shown to lower your good or HDL cholesterol. It is very important to eat less saturated and trans fats. Saturated fat is mostly found in animal products and products with high amounts of dairy fat like butter, cheese and cream. Trans fat is found mostly in products containing hydrogenated vegetable oils. Trans fat is also naturally found in animal products and some dairy products. Saturated and trans fats are typically solid at room temperature.
Dietary fats provide 9 kcal/g which is more than twice the calories provided by either, carbohydrates or proteins. Therefore, it is a major determinant of the energy density of a particular food.
How Much Fat Do I Need?
The amount of fat a person needs depends on age, sex, body size and composition, activity level, family history and health status. It is recommended to reduce the amount of fat in your diet, especially saturated and trans fats. It is advisable to choose more unsaturated fat and consume omega 3 fat.
The recommended dietary guidelines by WHO/FAO suggest 15 to 30% of your total energy should come from fat, with less than 10% of energy coming from saturated fat, 6-10 % from PUFA (5-8 % form omega-6 and 1-2 % from omega-3), less than 1% coming from trans fat and less than 300 mg of cholesterol per day.
It is important to include fat in your diet, but you’ll want to choose the right amount and the right kind of fat. If you’re getting most of your fat from lean meats, fish, and heart-healthy oils, you’ve already made fat your friend!
The Functions of Fats
The excess energy from the food we eat is incorporated into adipose tissue, or fatty tissue. Most of the energy required by the human body is provided by carbohydrates and lipids. As discussed in the Carbohydrates unit, glucose is stored in the body as glycogen. While glycogen provides a ready source of energy, it is quite bulky with heavy water content, so the body cannot store much of it for long. Fats, on the other hand, can serve as a larger and more long-term energy reserve.
Fats pack together tightly without water and store far greater amounts of energy in a reduced space. A fat gram is densely concentrated with energy, containing more than double the amount of energy as a gram of carbohydrate.
We draw on the energy stored in fat to help meet our basic energy needs when we’re at rest and to fuel our muscles for movement throughout the day, from walking to class, playing with our kids, dancing through dinner prep, or powering through a shift at work. Historically, when humans relied on hunting and gathering wild foods or on the success of agricultural crops, having the ability to store energy as fat was vital to survival through lean times.
Hunger remains a problem for people around the world, and being able to store energy when times are good can help them endure a period of food insecurity. In other cases, the energy stored in adipose tissue might allow a person to weather a long illness.
Unlike other body cells that can store fat in limited supplies, fat cells are specialized for fat storage and are able to expand almost indefinitely in size. An overabundance of adipose tissue can be detrimental to your health not only from mechanical stress on the body due to excess weight, but also from hormonal and metabolic changes. Obesity can increase the risk for many diseases, including type 2 diabetes, heart disease, stroke, kidney disease, and certain types of cancer. It can also interfere with reproduction, cognitive function, and mood. Thus, while some body fat is critical to our survival and good health, in large quantities it can be a deterrent to maintaining good health.
The membranes around the cells in our body physically separate the inside from the outside of the cell, and control the movement of substances in and out of the cells. They are mainly made of phospholipids, triglycerides and cholesterol (see Functions, Classification and Characteristics of Fats). Both length and saturation of the fatty acids from phospholipids and triglycerides affect the arrangement of the membrane and thereby its fluidity. Shorter chain fatty acids and unsaturated fatty acids are less stiff and less viscous, making the membranes more flexible. This influences a range of important biological functions such as the process of endocytosis in which a cell wraps itself around a particle to allow its uptake.1
The brain is very rich in fat (60%) and has a unique fatty acid composition; docosahexaenoic acid (DHA) is the major brain fatty acid. The lipids of the retina also contain very high concentrations of DHA.
Insulating and Protecting
The average body fat for a man is 18 to 24 percent and for a woman is 25 to 31 percent1, but adipose tissue can comprise a much larger percentage of body weight depending on the degree of obesity of the individual. Some of this fat is stored within the abdominal cavity, called visceral fat, and some is stored just underneath the skin, called subcutaneous fat. Visceral fat protects vital organs—such as the heart, kidneys, and liver. The blanket layer of subcutaneous fat insulates the body from extreme temperatures and helps keep the internal climate under control. It pads our hands and buttocks and prevents friction, as these areas frequently come in contact with hard surfaces.
It also gives the body the extra padding required when engaging in physically demanding activities such as ice skating, horseback riding, or snowboarding.
Carrier of Vitamins
In the diet, fat is a carrier for the fat-soluble vitamins A, D, E and K, and supports their absorption in the intestine. Consuming sufficient amounts of fatty foods that contain these vitamins is thus essential for adequate intake of these micronutrients.
Regulating and Signaling
Fats help the body to produce and regulate hormones. For example, adipose tissue secretes the hormone leptin, which signals the body’s energy status and helps to regulate appetite. Fat is also required for reproductive health; a woman who lacks adequate amounts may stop menstruating and be unable to conceive until her body can store more energy as fat. Omega-3 and omega-6 essential fatty acids help regulate cholesterol and blood clotting and control inflammation in the joints, tissues, and bloodstream.
Fats also play important functional roles in sustaining nerve impulse transmission, memory storage, and tissue structure. Lipids are especially focal to brain activity in structure and in function, helping to form nerve cell membranes, insulate neurons, and facilitate the signaling of electrical impulses throughout the brain.
Important Fats For The Body
- Digestion – Fat is not soluble in blood, so bile acids produced from cholesterol in the liver emulsify it along the way to make it bioavailable. It stores the fat soluble vitamins A, D, E, and K in the liver and fatty tissues. Because fat needs to be broken down through multiple processes that include the stomach, duodenum, liver, gall bladder, pancreas, and small intestine, it stays around for a long time and keeps you satiated.
- Transport – Fat is part of every cell membrane in the body. It helps transport nutrients and metabolites across cell membranes.
- Conversion – Your body utilizes fat for everything from activating hormones to building immune function.
- Energy extraction – Between meals or when glucose is not available, triglycerides are broken down and metabolized for energy, which in times of great need, the brain’s neurons can utilize.
- Nervous system – The axon is the part of a nerve (neuron) that transmits electrical signals from the brain throughout the body to initiate all functions. The axon’s protective coating is the myelin sheath and is made of 80% lipids (fats) that must be provided by the diet.
Keeping track of your total fat intake is the only way to know you’re getting the amount your body needs to make hormones, insulate organs and fill many more diverse roles. Two-thirds of your brain consists of essential fatty acids, according to the Franklin Institute. Your nerves can’t work properly without fats and you need them to digest vitamins A, D, E and K. Fats form special structures that safely carry cholesterol through your bloodstream, and they form a protective barrier in your skin.
Fats are your back-up source of energy when you don’t have enough carbohydrates, but the total fat in your diet is often a major source of calories. Additionally, some high-fat foods, such as sweets and snacks, lack nutrition. You’ll get 9 calories for every gram of fat you eat, compared to 4 calories in each gram of carbohydrate. Weight control primarily depends on balancing your caloric intake with the calories you burn, but the total amount of fats you consume may have an effect. Lower total fat intake leads to a small but significant loss in weight, according to a review published in the December 2012 issue of the “British Medical Journal.”