Fats, which consist of a wide group of compounds, are usually soluble in organic solvents and insoluble in water.
In this article, we will explain the different types of fats, which are considered good and bad, and what foods they can be found in.
What are fats?
Fats are called a range of different terms:
- Oils - any fat that exists in liquid form at room temperature. Oils are also any substances that do not mix with water and have a greasy feel.
- Animal fats - butter, lard, cream, fat in (and on) meats.
- Vegetable fats - olive oil, peanut oil, flax seed oil, corn oil, for instance.
- Fats or fatty acids - this refers to all types of fat. However, fats are commonly referred to as those that are solid at room temperature.
- Lipids - all types of fats, regardless of whether they are liquid or solid.
Lipids are an important part of the diet of all humans and many types of animals. Fat is stored in the body for many reasons.
There are several different types of fats and we'll take a look at these below:
Saturated fats are solid at room temperature and are sometimes called solid fat. They are totally saturated, meaning that each molecule of fat is covered in hydrogen atoms. Saturated fats increase health risks if a person consumes too much over a long period of time.
Where is saturated fat found?
Saturated fats can be found in meat, including bacon.
The highest levels of saturated fats can be found in meat (mammals), meat products, the skin of poultry, dairy products, many processed foods, such as cakes, biscuits, pastries, and chips, as well as coconut oil, palm oil, and cocoa butter.
A healthy diet includes less than 10 percent of its calories from saturated fats. That said, research shows it is never recommended to replace saturated fat intake with refined carbohydrates or sugar, as this worsens health.
Examples of healthy replacement foods would be nuts, seeds, avocado, beans, and vegetables.
Unsaturated fats, which include monounsaturated and polyunsaturated fats, are liquid at room temperature. They are mostly derived from plant oils and are classed as "good" fats:
Monounsaturated fat molecules are not saturated with hydrogen atoms - each fat molecule has only the space for one hydrogen atom.
Monounsaturated fats may lower LDL (low-density lipoprotein - bad) cholesterol, and keep HDL (high-density lipoprotein - good) cholesterol at higher levels. But, unless saturated fat intake is reduced, cholesterol levels may remain unchanged.
Many health professionals, however, say that these fats might still reduce a person's risk of developing heart disease. For instance, the Mediterranean diet, a well-researched and chronic disease-risk lowering diet, is full of monounsaturated fats.
Where are monounsaturated fats found?
Monunsaturated fats are found in olives and olive oil.
Olives, olive oil, nuts, peanut butter, and avocados.
In polyunsaturated fats, there are a number of spaces around each polyunsaturated fat molecule - they are not saturated with hydrogen atoms.
Nutritionists say that polyunsaturated fats are good for our health, especially those from fish, known as omega-3 polyunsaturated fatty acids.
Omega-3 fatty acids protect against heart disease by lowering blood cholesterol levels and possibly inflammation. Healthcare professionals say omega-3 polyunsaturated fatty acids may also help reduce the symptoms experienced by people who suffer from arthritis, joint problems in general, and some skin diseases.
The other type of polyunsaturated fats are omega-6 fatty acids. These are mostly found in vegetable oils and processed foods. An excessive intake of omega-6's, which is common in the standard American diet, may lead to increased inflammation.
Where are polyunsaturated fats found?
Polyunsaturated fats are found in oily fish including sardines, pictured here.
Oily fish (sardines, mackerel, trout, salmon, and herring), safflower, grapeseed, safflower, soybean, and sunflower oil. Nuts, seeds, and pastured eggs can also contain omega-3 fatty acids.
Trans fats are synthetically made, they do not naturally occur. Trans fats are created in an industrial process that adds hydrogen to liquid vegetable oils to make them more solid. They are also known as partially hydrogenated oils.
Trans fats are not essential for human life and they most certainly do not promote good health. Consuming trans fats increases LDL cholesterol level and lowers levels of HDL cholesterol; this, in turn, raises the risk of developing coronary heart disease and stroke about 3 times higher than other fats.
In fact, the Harvard School of Public Health estimates that trans fat intake is associated with 50,000 fatal heart attacks each year. They are also associated with an increased risk of developing type 2 diabetes.
Experts say that trans fats from partially hydrogenated oils are worse for your health than naturally occurring oils.
Trans fats have become popular because food companies find them easy to use and cheap to produce. They also last a long time and can give food a nice taste. As trans fats can be used many times in commercial fryers, they are commonly used in fast food outlets and restaurants. Several cities and states, including New York City, Philadelphia, and California, have banned or are in the process of banning trans fats.
Where are trans fats commonly found?
French fries (and other fried foods) are common sources of trans fats.
Fried foods, such as French fries, doughnuts, pies, pastries, biscuits, pizza dough, cookies, crackers, stick margarines, shortenings, packaged foods, fast foods, and many other baked foods.
If the nutritional labeling includes partially hydrogenated oils, it means that food has trans fats.
The take home message is that not all fats are equal. Staying informed and reading the labels can help individuals make good dietary choices, and replace unhealthy fats with healthy fats and fibrous plants.