Fats in Sports Nutrition
The third major macronutrient group is lipids (fats and oils).
Lipids have many vital body functions and are an essential part of every cell:
• In the diet, lipids are found with important essential fat-soluble vitamins. Such as vitamins A, D, E, and K.
• They are also a source of essential fatty acids (EFA’s), such as linoleic acid and alpha-linolenic acid, which have both a structural role and various metabolic roles in the body, including the production of neurotransmitters and steroid hormones.
• Lipids also make foods taste better-one of the characteristics that often leads to their over consumption.
Lipids, which consist of fats and oils, are high-energy yielding molecules composed mostly of carbon (C), hydrogen (H), and oxygen (O) (though lipids have a smaller number of oxygen molecules than carbohydrates have). This small number of oxygen molecules makes lipids insoluble in water, but soluble in certain organic solvents.
Fats and oils are therefore subcategories of lipids.
The Fats are solid at room temperature, and oils are liquid at room temperature.
Fats and oils consist mainly of triglyceride molecules. Other lipids include cholesterol and phospholipids.
The basic structure of lipids is a glycerol molecule consisting of three carbons, each attached to a fatty-acid chain.
Collectively, this structure is known as a triglyceride, or sometimes it is called a triacylglycerol.
Triglycerides are the major form of energy storage in the body (whereas carbohydrates are the body’s major energy source), and are also the major form of fat in foods.
The energy contained in a gram of lipids is more than twice the amount in carbohydrates and protein, with an average of 9 kcal/g.
Lipids provide the body with fuel.
Aid in the absorption of fat-soluble vitamins.
Act as energy store-houses within cells.
And supply the essential fatty acids important to growth, development, and health maintenance.
In addition, lipids provide protective padding for body structures and organs.
Supply building blocks for other molecules, serve as building blocks for all cell membranes and other cell structures.
And provide the body with insulation from cold.
Dietary fat has been blamed for many health problems, however fat is actually an essential nutrient for optimal health.
There is an optimal level of body fat for health and for athletic activity. When that optimal level is exceeded, too much dietary fat can lead to problems with health as well as athletic performance.
Types of Dietary Fat
Lipids can be broken down into two types based on the chemical structure of their longest, and therefore dominant, fatty acid:
Whether a lipid is solid or liquid at room temperature largely depends on its property of being saturated or unsaturated.
Lipids from plant sources are largely unsaturated, and therefore liquid at room temperature.
Lipids that are derived from animals contain a higher amount of saturated fats, and they are therefore solid at room temperature.
An exception to this rule is fish, which, for the most part, contain unsaturated fat.
The important difference between saturated and unsaturated fatty acids is that saturated fatty acids are the most important factor that can increase a person’s cholesterol level. An increased cholesterol level may eventually result in the clogging of blood arteries and, ultimately, heart disease.
Saturated fats: are found primarily in animal sources like meat, egg yolks, yogurt, cheese, butter, milk.
This type of fat is often solid at room temperature.
Too much saturated fat has been linked to health problems such as high cholesterol and heart disease.
Because of this, saturated fat should be limited to no more than 10% of total daily calorie intake.
Unsaturated fats include:
• Monounsaturated fats
• Polyunsaturated fats
Are typically found in plant food sources and are usually liquid at room temperature.
Unsaturated fats have health benefits such as lowering cholesterol and reducing the risk of heart disease.
Common food sources include olive and canola oil, avocados, fish, almonds, soybeans and flaxseed.
Mono-unsaturated fatty acids: Monounsaturated fats, also known as omega-9, are common components of animal fat and vegetable oil.
Two omega−9 fatty acids important in industry are:
Oleic acid (18:1, n−9), which is a main component of olive oil, macadamia oil and other monounsaturated fats.
Erucic acid (22:1, n−9), which is found in rapeseed, wallflower seed, and mustard seed. Rapeseed with high erucic acid content is grown for commercial use in paintings and coatings as a drying oil.
Unlike omega-3 fatty acids and omega-6 fatty acid, omega−9 fatty acids are not classed as essential fatty acids (EFA).
This is both because they can be created by the human body from unsaturated fat, and are therefore not essential in the diet.
Mono-unsaturated fatty acids, such as olive oil, avocados and almonds have been shown to reduce total cholesterol and LDL (bad) cholesterol and increase HDL (good) cholesterol hence improving heart health.
Polyunsaturated fats: found in sunflower oil, safflower oil and corn oil are not thought to contribute to heart disease but don’t offer the same protection as monounsaturated fats.
These are divided into a further two groups: Omega 3 and Omega 6 fats.
Omega 3 fatty acids: are found in foods such as oily fish/ blue fish such as pilchards, sardines, salmon, mackerel, fresh tuna and trout, as well as some seeds and nuts such as linseed and walnuts.
Omega 3 fats do not directly affect cholesterol levels, but research shows they help in the prevention of heart attacks, increases concentration, reduces the chances of forming a blood clots and more recently aids in inflammatory disorders such as arthritis and Crohn’s disease.
Having 2 small portions of oily fish a week should ensure an adequate intake of omega 3’s.
Omega 6 fatty acids: are those such as canola or sunflower oil have been shown to help reduce total cholesterol.
Trans fat: Trans fats, or trans-unsaturated fatty acids, trans fatty acids, are a type of unsaturated fats that occur in small amounts in nature but produced industrially from vegetable fats for use in margarine, snack food, packaged baked goods and frying fast food.
Trans fat has been shown to consistently be associated, in an intake-dependent way, with increased risk of coronary heart disease, a leading cause of death in Western nations.
Essential Fatty Acids
Essential fatty acids are a class of polyunsaturated fats that have received a lot of attention in the media recently.
They are thought to be cardio-protective and may help prevent a range of other illnesses.
The two primary essential fatty acids are:
• Linoleic acid (an omega-6 fatty acid)
• Alpha-linolenic acid (an omega-3 fatty acid)
These two fatty acids cannot be made in any significant amount by the body; therefore, it is essential that they are ingested on a daily basis from the diet.
Under certain circumstances, a third fatty acid called arachidonic acid, which the body makes from linoleic acid, becomes essential if dietary intake of linoleic acid is deficient.
Linoleic acid and alpha-linolenic acid are both unsaturated fatty acids that are eighteen carbon atoms long.
In addition to their structural roles in the body and their roles as precursors of important biomolecules and hormones, these two fatty acids are also used for energy.
The ratio of omega-6 to omega-3 is very important for many physiological functions.
Getting the right balance with this ratio can help to improve the immune response, coagulation and cell signalling- among other things.
For example, the right ratio can help to decrease inflammation, decrease blood pressure, prevent irregular heart beat and encourage healthy blood flow.
The current recommended ratio of omega 6: omega 3 is between 5:1 and 10:1 but in the western diet, the current average is 15:1 to 30:1.
It appears that on the whole, we tend to be very good at getting enough omega 6 in the diet, but it is omega-3 that we need to make a consistent effort to consume.
Try to increase your omega-3 intake by eating foods rich in omega-3 such as: Free range eggs (more than normal eggs) – Flaxseed – Salmon – Chia Seeds – Walnuts – Sardines – Mackerel – Edamame-Beef.
How Fat Provides Energy for Sports
Using fat as fuel depends on the event’s duration and the athlete’s condition.
As duration increases and/or intensity decreases, the utilization of fat as an energy source increases.
For moderate exercise, about half of the total energy expenditure is derived from free fatty acid metabolism.
If the event lasts more than an hour, the body may use mostly fats for energy.
Fat intake should be adequate enough to provide essential fatty acids and fat soluble vitamins (A, D, E & K).
You should be getting around 20-25% of your daily energy from fats and this should never drop below 15%.
In practical terms, try eating 2-3 portions of ‘healthy fats’ per day.
Using fat for fuel for exercise, however, is dependent upon these important factors:
Fat is slow to digest and be converted into a usable form of energy. It can take up to 6 hours.
Converting stored body fat into energy takes time. The body needs to breakdown fat and transport it to the working muscles before it can be used as energy.
Converting stored body fat into energy takes a great deal of oxygen, so exercise intensity must decrease for this process to occur.
For these reasons, athletes need to carefully time when they eat fat, how much they eat and the type of fat they eat.
In general, it’s not a great idea to eat fat immediately before or during intense exercise.
Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA)
These two fatty acids were plunged into the media limelight in the 1980s when scientists examining the traditional diet of Eskimos in Greenland – high in fats and animal proteins – discovered that these people experienced a very low rate of cardiovascular diseases.
Upon further examination, researchers discovered that one of the health-contributing factors was the cholesterol-lowering effect of EPA and DHA-also referred to as omega-3 fatty acids.
There are studies documenting the improvement of athletic performance using anywhere from 2,000 mg to 4,000 mg per day of EPA and DHA from eating fish and taking EPA/DHA dietary supplements.
Researchers have observed improvements in strength and aerobic performance as well.
These functions include growth hormone production, anti-inflammatory action, enhanced oxygen metabolism, and lowered blood viscosity (blood-thinning effects).
This leads to better oxygen and nutrient delivery to the muscles. And improved recovery after rigorous bouts of exercise and training.
In addition to getting EPA and DHA through supplements, these fatty acids are found in high amounts in cold-water fish, such as cod, salmon, sardines, trout, and mackerel, and in lower amounts in tuna fish – an economical source of low-fat protein.
Despite its bad press, cholesterol is actually essential for many important bodily functions.
There are essentially two types of cholesterol:
• Low-density lipoprotein (LDL)(bad)
• High-density lipoprotein (HDL)(good)
LDL is known as the “bad” cholesterol because it carries and then deposits cholesterol at the artery walls.
HDL on the other hand, is known as “good” cholesterol because it acts as a scavenger removing cholesterol from artery walls and transporting it to the liver to be excreted.
Although some foods like cream, butter, ice cream, egg yolks, shellfish and red meats contain cholesterol. It’s a high intake of saturated fat that causes the body to synthesize too much cholesterol. The maximum amount of dietary cholesterol recommended each day is 300mg.