Fats and Oils: Types, Health Benefits, and Facts
Author: Disabled World (DW)
Updated/Revised Date: 2 Nov 2026
Table of Contents:
Synopsis - Definition - About This Section - FAQs - Publications - Subtopics
Synopsis
Learn about good and bad fats and oils, including saturated, unsaturated, and trans fats, omega fatty acids, and how each affects your health and cholesterol.
At a Glance
- 1 - The human body can produce all but two of the fatty acids it needs.
- 2 - Oil refers to fats that are liquid at room temperature, while fat refers to those that are solid.
- 3 - In frying tests, olive oil stayed the most stable while sunflower oil degraded fastest when pan-fried.
- 4 - Hydrogenation sparges oil with hydrogen at high heat using a catalyst, typically a powdered nickel compound.
Topic Definition
- Fats and Oils
Fats and oils are one of the three main macronutrients, alongside carbohydrate and protein, and they belong to a broad group of compounds built from long-chain organic acids known as fatty acids. Chemically, they are esters formed when these fatty acids combine with glycerol, producing the triglycerides that make up most edible fats. The everyday difference between the two terms comes down to physical state: an oil is generally liquid at normal room temperature, while a fat is solid. Beyond providing a concentrated source of energy, fats and oils supply essential fatty acids the body cannot make on its own and serve both structural and metabolic roles that are vital to human health.
Overview
This section of Disabled World contains a wide variety of information on good and bad fats and oils - including the Omega fatty acids, trans fats, saturated and unsaturated fats. Fat is defined as one of the three main macronutrients: fat, carbohydrate, and protein. Fats are a wide group of compounds whose basis is in long-chain organic acids, called fatty acids. More particularly, fats are esters of such organic acids formed with the alcohol glycerol. Glycerol is a triol, meaning that it has three chemically active -OH (hydroxyl) groups.
Oil is the term usually used to refer to fats that are liquids at normal room temperature, while fat is usually used to refer to fats that are solids at normal room temperature.
Vegetable Fats
Vegetable fats and oils are lipid materials derived from plants. Physically, oils are liquid at room temperature, and fats are solid. Chemically, both fats and oils are composed of triglycerides, as contrasted with waxes which lack glycerin in their structure. Although many parts of plants may yield oil, in commercial practice, oil is extracted primarily from seeds.
Hydrogenated Oils
Unsaturated vegetable fats and oils can be transformed through partial or complete hydrogenation into fats and oils of higher melting point. The hydrogenation process involves "sparging" the oil at high temperature and pressure with hydrogen in the presence of a catalyst, typically a powdered nickel compound.
Essential Oils
An essential oil is a concentrated, hydrophobic liquid containing volatile aroma compounds from plants. They are also known as volatile or ethereal oils, or simply as the "oil of" the plant material from which they were extracted, such as oil of clove. An oil is "essential" in the sense that it carries a distinctive scent, or essence, of the plant. Essential oils do not as a group need to have any specific chemical properties in common, beyond conveying characteristic fragrances. They are not to be confused with essential fatty acids.
Macerated Oils
Macerated oils are vegetable oils to which other matter, such as herbs, has been added. Herbalists and aromatherapists use not only pure macerated oils, but blends of these oils, as well, and may macerate virtually any known herb. Base oils commonly used for maceration include almond oil, sunflower oil, and olive oil, as well as other food-grade triglyceride vegetable oils.
Fatty Acids
A fatty acid is a carboxylic acid often with a long unbranched aliphatic tail (chain), which is either saturated or unsaturated. Carboxylic acids as short as butyric acid (4 carbon atoms) are considered to be fatty acids, whereas fatty acids derived from natural fats and oils may be assumed to have at least eight carbon atoms, caprylic acid (octanoic acid), for example.
The human body can produce all but two of the fatty acids it needs.
These two, linoleic acid (LA) and alpha-linolenic acid (ALA), are widely distributed in plant oils. In addition, fish oils contain the longer-chain omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Other marine oils, such as from seal, also contain significant amounts of docosapentaenoic acid (DPA), which is also an omega-3 fatty acid. Although the body to some extent can convert ALA into these longer-chain omega-3 fatty acids, the omega-3 fatty acids found in marine oils help fulfill the requirement of essential fatty acids (and have been shown to have wholesome properties of their own).
Saturated or Trans Fatty Acids
A trans fatty acid (commonly shortened to trans fat) is an unsaturated fatty acid molecule that contains a trans double bond between carbon atoms, which makes the molecule less 'kinked' in comparison to fatty acids with cis double bonds. These bonds are characteristically produced during industrial hydrogenation of plant oils.
These fats are solid at room temperature and are contained in food products like butter, shortening, or the fat on meat products. Some types of oils, like palm kernel oil and coconut oil, contain saturated fat. Whole dairy foods and meat also contain small amounts of natural trans fats.
Artificial trans fat is formed when hydrogen is added to vegetable oils, a process called partial hydrogenation, which increases the shelf life and flavor of food containing these fats. Trans fats were long found in many types of pre-packaged items, like cookies, crackers, and potato chips, and in many fried foods, such as french fries and doughnuts. In the United States, the Food and Drug Administration (FDA) ruled in 2015 that partially hydrogenated oils, the main source of artificial trans fats, are not safe for use in food, and manufacturers had to stop adding them from June 18, 2018. Saturated fat and trans fat raise blood cholesterol levels, increasing a person's risk of developing heart disease.
Research suggests that amounts of trans fats correlate with circulatory diseases such as atherosclerosis and coronary heart disease more than the same amount of non-trans fats, for reasons that are not fully understood. It is known, however, that trans fats raise the LDL ("bad") cholesterol and lower the HDL ("good") cholesterol. They have also been shown to have other harmful effects, such as increasing triglycerides and Lp(a) lipoproteins. They are also thought to cause more inflammation, which is thought to occur through damage to the cells lining the blood vessels.
Unsaturated Fats
These fats are usually liquid at room temperature, and they can be polyunsaturated or monounsaturated. Polyunsaturated fats help your body rid itself of newly formed cholesterol. They keep your blood cholesterol levels down and reduce cholesterol deposit build up in your artery walls. Examples of polyunsaturated fats include fish and fish oil, sunflower oils, corn, and soybean. Monounsaturated fat is found in olives, olive and canola oil, most types of nuts and their oils and avocados.
Olive Oil, More Stable and Healthy than Seed Oils for Frying
Scientists report in ACS Journal of Agricultural and Food Chemistry that olive oil withstands the heat of the fryer or pan better than several seed oils to yield more healthful food.
They note that different oils have a range of physical, chemical and nutritional properties that can degrade oil quality when heated. Some of these changes can lead to the formation of new compounds that are potentially toxic. By-products of heating oil can also lower the nutritional value of the food being fried.
The team wanted to find out which cooking oil can maintain its quality under high heat and repeated use. The researchers deep-fried and pan-fried raw potato pieces in four different refined oils, olive, corn, soybean and sunflower, and reused the oil 10 times. They found that olive oil was the most stable oil for deep-frying at 320 and 374 degrees Fahrenheit (160 and 190 degrees Celsius), while sunflower oil degraded the fastest when pan-fried at 356 degrees Fahrenheit (180 degrees Celsius).
They conclude that for frying foods, olive oil maintains quality and nutrition better than seed oils.
Facts on Fats and Oils
- Fat is an important foodstuff for many forms of life, and fats serve both structural and metabolic functions.
- There are many kinds of fats, but each is a variation on the same chemical structure.
- Fats are also sources of essential fatty acids, an important dietary requirement.
- Fats and oils are categorized according to the number and bonding of the carbon atoms in the aliphatic chain.
- Despite long-standing assertions to the contrary, fatty acids can also be used as a source of fuel for brain cells.
- Organic oils are produced in remarkable diversity by plants, animals, and other organisms through natural metabolic processes.
- Several edible vegetable and animal oils, and also fats, are used for various purposes in cooking and food preparation.
- Fat is one of the three main macronutrients: fat, carbohydrate, and protein.
- Fats that are saturated fats have no double bonds between the carbons in the chain.
- Unsaturated fats have one or more double bonded carbons in the chain.
Frequently Asked Questions
How much fat should you eat each day?
Guidelines vary by age, sex, and activity level, but fat commonly makes up around 20 to 35 percent of daily calories, with an emphasis on unsaturated sources over saturated and trans fats.
Are all saturated fats bad for you?
Saturated fats can raise blood cholesterol and are best limited, though nutrition science continues to explore how different sources affect health, so moderation and overall diet quality matter most.
What is the difference between omega-3 and omega-6 fatty acids?
Both are essential polyunsaturated fats, but omega-3s such as those in fish oil are linked to anti-inflammatory benefits, while omega-6s are common in many plant oils and are needed in balance.
Why were trans fats banned or restricted in many countries?
Artificial trans fats raise bad cholesterol and lower good cholesterol while increasing heart disease risk, which led many governments to limit or remove them from the food supply.
Can eating fat help you lose weight?
Healthy fats can support weight management by promoting fullness and steady energy, but because fat is calorie dense, overall calorie intake still determines whether weight is gained or lost.
Which oils are best for high-heat cooking?
Oils with greater stability and higher smoke points, such as olive oil, tend to hold up better under high heat and repeated use than more delicate seed oils.
Do plant-based oils contain cholesterol?
Cholesterol is found only in animal products, so pure plant-based oils contain none, although the type of fat they provide still affects the body's cholesterol levels.
What is the smoke point of an oil?
The smoke point is the temperature at which an oil starts to smoke and break down, producing harmful compounds and bitter flavors. Refined oils such as avocado and peanut oil have higher smoke points than unrefined oils such as extra virgin flaxseed oil.
Curated and edited by Ian C. Langtree, Founder and Editor-in-Chief, Disabled World. This section is maintained by the Disabled World editorial team. Last updated: