Dietary Fats: Know Which Type to Choose

Dietary Fats

Why are trans fats bad for us, polyunsaturated and monounsaturated fats good for us, and saturated fats somewhere in-between?
For years, we were urged to banish it from our diets whenever possible. We switched to low-fat foods. But the shift didn't make us healthier, probably because we cut back on healthy fat as well as harmful ones. You may wonder isn't fat bad for you, but our body needs some fat from food. It's a major source of energy. It helps us absorb some vitamins and minerals.
Fat is needed to build cell membranes, the vital exterior of each cell, and the sheaths surrounding nerves. It is essential for blood clotting, muscle movement, and inflammation. For long-term health, some fats are better than others. Good fat include monounsaturated and polyunsaturated fat. Bad ones include industrial-made trans fat. Saturated fat fall somewhere in the middle but is considered as bad one.
Fats are one of the three main macronutrients, along with carbohydrates and proteins. Fat is a type of nutrient, and just like protein and carbohydrates.  Our body needs some fat for energy, to absorb vitamins, and to protect our heart and brain health. Our body makes its own fat from taking in excess calories. Some fats are found in the foods we eat — these are called dietary fats. Dietary fat is a macronutrient that provides energy for our body.
Fat is essential to our health because it supports a number of our body's functions. Some vitamins, for instance, must have fat to dissolve so that they can be used by our body. Some vitamins require fat in order to dissolve into our bloodstream and provide nutrients.
Fat is an important foodstuff for many forms of life, and fats serve both structural and metabolic functions. They are a necessary part of the diet of most heterotrophs (including humans) and are the most energy dense, thus the most efficient form of energy storage.

Dietary Fat and Cholesterol

Dietary fat also plays a major role in maintaining our cholesterol levels. Cholesterol is a fatty, wax-like substance that our body needs to function properly. In and of itself, cholesterol isn’t bad. But when we get too much of it, it can have a negative impact on our health. As with dietary fat, there are good and bad types of cholesterol.
The key is to keep LDL levels low and HDL high, which may protect against heart disease and stroke.
Conversely, high levels of LDL cholesterol can clog arteries and low HDL can be a marker for increased cardiovascular risk.
Rather than the amount of cholesterol we eat, the biggest influence on our cholesterol levels is the type of fats we consume. So instead of counting cholesterol, it’s important to focus on replacing bad fats with good fats.

GoodFats vs. Bad Fats

Since fat is an important part of a healthy diet, rather than adopting a low-fat diet, it’s more important to focus on eating more beneficial “good” fats and limiting harmful “bad” fats.

Healthy or “Good” Fats (Unsaturated Fats)

The potentially helpful types of dietary fat are primarily unsaturated fats:
Monounsaturated Fatty acids : This type of fat is found in a variety of foods and oils. Studies show that eating foods rich in monounsaturated fatty acids instead of saturated fats improves blood cholesterol levels, which can decrease our risk of heart disease and may also help decrease the risk of type 2 diabetes.
Polyunsaturated Fatty acids : This type of fat is found mostly in plant-based foods and oils. Evidence shows that eating foods rich in polyunsaturated fatty acids instead of saturated fats improves blood cholesterol levels, which can decrease our risk of heart disease and may also help decrease the risk of type 2 diabetes.
Omega-3 fatty acids : One type of polyunsaturated fat is made up of mainly omega-3 fatty acids and may be especially beneficial for heart health. Omega-3, found in some types of fatty fish, appears to decrease the risk of coronary artery disease. There are plant sources of omega-3 fatty acids. However, it hasn't yet been determined whether replacements for fish oil — plant-based or krill — have the same health effects as omega-3 fatty acid from fish.

Unhealthy or “Bad” Fats (Saturated Fats)

There are two main types of potentially harmful dietary fats:
Saturated Fat : This type of fat comes mainly from animal sources of food, such as red meat, poultry and full-fat dairy products. Saturated fats raise high-density lipoprotein (HDL or "good") cholesterol and low-density lipoprotein (LDL or "bad") cholesterol levels, which may increase our risk of cardiovascular disease.
Trans Fat : This type of fat occurs naturally in some foods in small amounts. But most trans fats are made from oils through a food processing method called partial hydrogenation. These partially hydrogenated trans fats can increase total blood cholesterol, LDL cholesterol and triglyceride levels, but lower HDL cholesterol. This can increase our risk of cardiovascular disease.
Most fats that have a high percentage of saturated fat or that contain trans fat are solid at room temperature. Because of this, they're typically referred to as solid fats. They include beef fat, pork fat, butter, coconut oil, shortening and stick margarine.

Fatty Acids and Human Health

Dietary consumption of fatty acids has effects on human health. Studies have found that replacing saturated fats with unsaturated fats in the diet reduces risk of cardiovascular disease. For example, a 2015 systematic review of randomized control trials by the Cochrane Library concluded: "Lifestyle advice to all those at risk of cardiovascular disease and to lower risk population groups should continue to include permanent reduction of dietary saturated fat and partial replacement by unsaturated fats."
Numerous studies have also found that consumption of trans fats increases risk of cardiovascular disease. The Harvard School of Public Health advises that replacing trans fats and saturated fats with monounsaturated and polyunsaturated fats is beneficial for health. A 2014 meta-analyses of randomized controlled trials found that reducing fat and cholesterol intake does not affect cardiovascular disease or all cause mortality.