Fats are a big topic of discussion these days. Everybody wants to lose fat. Everywhere you go, you see things like “low fat”, “no fat” or “fat free”. What are fats and do they deserve the bad reputation that they get?
Fats are one of the three main macronutrient types for your body, together with proteins and carbohydrates. Unlike carbohydrates, some types of fats are considered essential for your body and life. This means that you need to get them from the outside by ingesting food, otherwise your body cannot produce some elements necessary in order to keep functioning. Fats are often misunderstood by the general public. They have a very bad image, however in fact, many types of fats are good for you and your health. Your body needs fats in order to perform its functions. The key here is in the types of fats that you consume and also the amount. If you want to gain weight and muscle, then fats should definitely be a part of your diet.
Fats are a wide group of compounds that are usually soluble in organic solvents, but insoluble in water. They are also called triglycerides, because chemically they are triesters of glycerol and any of the several types of fatty acids. When triglycerides are metabolized, the glycerol in them gets converted to glucose, which means usable energy for the body. The enzymes that break them down are called lipases and are produced in the pancreas.
Fats are a subset of a wider group of compounds called lipids. Lipids include triglycerides, phospholipids, and also sterols (one type of sterol is called cholesterol). You get all of these types of lipids when you eat, however triglycerides make up the most significant group of lipids in our diets. They make up around 95% of the lipids in our food and bodies.
Sources of Fats
Fats come in two forms: liquid and solid. The ones that at room temperature come in liquid form are called oils. Most oils come from plants (edible plant fats). Examples of these oils include ones from: palms, soybean, rapeseed (a subtype of rapeseed is for example canola oil), sunflower seeds, peanuts, cottonseeds, palm kernels, coconuts, olives, corn…etc. Solid fats usually come from animals. The main example are the fats from under the skin of different animals. In some cases, fats from animals can also come as oils, for example fish oils.
Sources of “good fats”:
Structure of Fats
All triglycerides have similar structures, being composed of a glycerol molecule and three fatty acids attached to it. Fatty acids are one of the main constituent parts of fats, but what are they? A fatty acid is a type of carboxylic acid and consists of a long hydrocarbon chain capped by a carboxyl group (COOH). They can serve as fuel and also form adenosine triphosphate, otherwise known as ATP. ATP can basically be described as the engine of the body, as these enzyme molecules can store energy and then release it when it is necessary.
Fatty acids differ in length and how “saturated” they are. They are usually composed of carbon molecules attached to hydrogen molecules. These are attached together through different types of bonds, for example single or double bonds. Saturation is determined by the number of hydrogen attached. If the maximum number possible of hydrogen molecules is attached, then the fat is saturated. If there are holes, then the fat is unsaturated.
1) Saturated Fat
Saturated fats usually come from animal sources (although palm and coconut oils are also major sources of saturated fats), and a lot of times are solid at room temperature. They are also usually pretty stable. They also contain no double bonds between the different carbons in their chains and the number of carbons in each chain can differ from 3 to 36.
2) Unsaturated Fat
Most unsaturated fats come from plant sources and are usually liquid at room temperature (therefore referred to as oils). Unsaturated fats are highly unstable, especially at room temperature. The carbons in their chains usually contain at least some double bonds and there are certain hydrogen molecules missing.
There are two kinds of unsaturated fats: monounsaturated and polyunsaturated. Monounsaturated fats are composed of fatty acids that have only one double bond in their carbon chain and the rest are single bonds. This means there is room for only one more pair of hydrogen atoms. On the other hand, polyunsaturated fats have several double bonds and several hydrogen atoms can be accepted and linked into the chain. These double bonds can be arranged in two ways, either as -cis or -trans. Cis fats are usually naturally occurring, while trans fats are usually manufactured.
There are many different types of polyunsaturated fats. Two fatty acids are considered essential: linoleic, linolenic, while arachidonic acids can sometimes be considered essential if the body is deficient in linoleic acid or cannot convert it to arachidonic acid. The spellings of some of these acids might be almost the same, but watch out, because they are different. 🙂 Linoleic acid is a type of Omega-3 acid, while linolenic and arachidonic are both examples of Omega-6 acids.
Roles of Fats
So what roles do fats play in the body? Fats in the body primarily serve the role of energy reserve and insulation. They can be burned down and turned to energy for the body when it is needed and not enough is being supplied at that moment through the ingestion of food. Fats also serve as components of cell membranes. They are also important for the digestion and transportation of vitamins A, D, E and K, as these are fat soluble and need fats in order to be processed and used in the body.
These are the main roles of fat in the body:
1) Storage and provision of energy: Fats store energy in the body for subsequent use. Fats are composed of glycerol bound to fatty acids. When needed, the fats storage can be accessed and the glycerol can be broken down into glucose for immediate use. The process of conversion of fats into glucose is called gluconeogenesis. Fats can also be used as immediate energy themselves and provide much more energy per gram (9 calories per gram) than carbohydrates or protein. They are used as energy when carbohydrates are not available.
2) Provide structure: Fats form the structural elements of cells and cell membranes.
3) Supply of essential fatty acids: These essential fatty acids are essential for the normal functioning of different types of tissue in the body.
4) Transportation: Some vitamins (A, D, E, K…etc.) are only fat soluble and so fats transport them throughout the body where they are needed.
5) Insulation: Fats stored in adipose tissue provide insulation for the body. They can also protect vital body organs.
6) Coverings of nerves: Nerves are covered by substances made of fats and so this is essential for nerves to carry impulses.
7) Important in the production of hormones: Some fats are very important in the production of hormones.
8) Production of milk in mothers: Fats also have temporary importance in females, as they are necessary for the production of milk in mothers.
Problems with Fats
Consumption of too many fats can cause an unhealthy weight gain and obesity. If you are underweight, then you need to gain weight and so any type of weight gain is positive, however there are limits and you don’t want to have too much fat and look like the Pillsbury Dough Boy. Too much fat can also cause too much bad cholesterol, which can clog up your arteries and cause all kinds of problems.
Saturated fat is usually considered not healthy for you, however recent studies show that there are certain positive health benefits. It is usually the unsaturated fats that are considered healthy for you, however even there we have to make a distinction. So when people talk about “healthy fats”, they usually mean unsaturated fats. Some unsaturated fats are also considered unhealthy however. The trans fats, which are usually a result of artificial processes, are considered unhealthy and should be reduced to a minimum level in your diet.
Fats are an important part of any diet. They are especially important if you want to gain weight. They should compose around 20-30% of your diet. However don’t gobble down any type of fat. Try to eat “healthy” fats from natural sources such as fish oil or avocados. These are sources of essential fats and have positive benefits for your body and health.
Your diet should incorporate both saturated and unsaturated fats and try to avoid trans fats. Remember that moderation is key here. While eating too much saturated fats can be unhealthy for you, you still need to incorporate saturated fats in your diet, especially if you are trying to gain weight.