Fats and oils are an extremely important part of a healthy diet and are also highly beneficial in fat loss diets. For many years, so called nutritional experts have blamed dietry fat for causing obesity, high cholesterol levels and heart disease, however this statement is far from the truth. These people have been victims of misinformation from poorly conducted tests and research involving fat. Fat is only harmful when consumed in excess, just like every other macronutrient.
What is fat?
Fat is an energy source which provides 9 calories per gram and is made up of a glycerol backbone which is esterified with 3 fatty acids to form a triglyceride and 3 molecules of water. These fatty acids determine whether the fat is saturated (no double bonds), monounsaturated (one double bond) or polyunsaturated (more than 1 double bond).
Saturated Fat
Saturated fat is mainly found in animal products and are naturally a solid at room temperature. Saturated fats tend to have a negative effect on blood lipids however this is not always the case depending on the persons activity levels. This type of fat is not essential.
Saturated fats can be found in meat & dairy products
Polyunsaturated Fat
Polyunsaturated fat can be split up into 2 categories : Omega 3 polyunsaturated fat & Omega 6 polyunsaturated fat. Polyunsaturated fats are primarily found in vegetable oils and are liquid at room temperature. These fats have a positive effect on human health however excess consumption of omega 6 and lack of omega 3 have a negative effect on human health. These types of fat are essential.
The most important omega 3 fatty acid is alpha-linolenic acid (ALA). This can be altered inside the body to form other fatty acids, with the most important being eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
The most important omega 6 fatty acid is linoleic acid (LA) . This can be altered inside the body to form other fatty acids, with the most important being gamma-linolenic acid (GLA) and arachidonic acid (AA).
Polyunsaturated Omega 6 can be found in vegetable oil, corn oil, safflower oil, sunflower oil, peanut oil, and sesame oil
Polyunsaturated Omega 3 can be found in fish oil, flaxseed oil, canola oil, walnut oil, and green leafy vegetables
Monounsaturated Fat
Monounsaturated fat is present in almost all foods which contain fat and are liquid at room temperature. Monounsaturated fat can have a positive effect on health however this is a non essential fat.
Monounsaturated fat can be found in olive oil & some nuts
Trans FatTrans fatty acids are a man made fat produced by adding hydrogen to vegetable oil to make it semi-solid and increase the shelf life. Margarine is probably the example most people are familiar with although trans fatty acids are found in almost all processed foods. Of all the fats, trans fatty acids have the worst effect on blood lipids, immune system and overall health. These fats should be avoided at all costs.
Trans fat can be found in anything “hydrogenated” mainly margarine
Fat balance and benefits
When we eat fat, our body shuttles lipids into cell membranes where they bind to phosphates. These are better known as phospholipids. Phospholipids make up the barrier between the inside and outside of the cells. These phospholipids are important because they’re used to make hormone-like molecules called eicosanoids.
Eicosanoids are involved in many bodily functions. If we’re consuming a lot of omega 6 fatty acids, we produce phospholipids with high omega 6 content. The eicosanoids are then made from the omega 6s. The same rule applies for eating omega 3s.
The eicosanoids made from omega 3’s and omega 6’s have very different functions. One of the main differences is that omega 6 eicosanoids are very pro-inflammatory, whereas omega 3 eicosanoids are very weakly inflammatory. A dietary shift towards more omega 3s has been shown to help in a variety of diseases from asthma to cardiovascular disease, but it also has the potential to be of benefit to athletes. Since they have anti-inflammatory properties, they can reduce DOMS (delayed onset muscle soreness) and speed up recovery of broken muscle tissue from hard workouts.
High levels of omega 6’s have also been linked to greater insulin resistance. High levels of blood insulin inhibit HSL (Hormone sensitive lipase) which is an enzyme responsible for mobilising fatty acids from cells stored in adipose tissue. This will hinder your ability to lose fat. Fat cells (Adipocytes) become more insulin resistant with higher levels of omega 3’s which can help reduce fat storage.
Monounsaturated fats work in a similar way to polyunsaturated fats in that they are shuttled into cell membranes and converted to phospholipids. Monounsaturated fats are beneficial in that they prevent the oxidative degradation of lipids. More simplistic this means it prevents free radicals stealing electrons from cell membranes which results in cell damage.
Saturated fats are an important part of a bodybuilders diet who is looking to gain mass. Saturated fat has a positive effect on sex hormone production. Increased testosterone means bigger and stronger muscles and decreased recovery times.
Another important function of fat is that it decreases the absorption rate of nutrients in the small intestine. When fat is ingested, CCK (cholecystokinin) is released, which is a hormone that influences gastric motility. This hormone stimulates the contraction of the pyloric sphincter which is a ring of muscles that control the rate of passage of materials through the stomach to the small intestine and therefore slowing gastric emptying. We can take advantage of this effect by combining fat with proteins to slow the absorption in long periods of fasting (sleep).
