The Fundamentals of Nutrition The basics - by understanding macronutrients and the roles they play gives us a clearer picture of the fundamentals of nutrition.
Macronutrients are nutrients that deliver energy in the form of calories. Macro (large) nutrients are substances needed for growth, metabolism, and other body functions.
There are 3 macronutirents that deliver energy to your body are carbohydrates, protein, and fat. Alcohol also provides 7 calories per gram, but it is not considered a macronutrient because we don't need it to survive. It provides empty calories, giggles, headaches and more ;-)
Carbohydrates
Carbohydrates have many roles but the two primary ones are that they provide glucose for the brain (its only energy source) and energy for the working muscles. Carbs are stored in the liver and in the muscles as glycogen. Glycogen allows us to sustain prolonged exercise, pretty critical in an endurance based sport such as triathlon.
Carbs are composed of sugars, starches, and fibers. These are all absorbed and metabolised differently. There are different types of sugars, starches and fibers and most foods will contain a combination of all of the above. You must know that not all carbs are created equal. As we are well aware carbs can impact weight, performance and our mood. Carbohydrates provide four calories of energy per gram. As stated above, different types of carbs are absorbed into the body at different rates. Sugars like sucrose (table sugar) are absorbed relatively quickly compared to starches and fiber that is absorbed the slowest. Quick absorption causes a rapid spike in blood sugar levels. The impact on this the subsequent crash we get. Why? because the body has a regulatory system that try's to keep us in a state of equilibrium, when we have a rapid blood glucose spike the body responds by releasing insulin, when the blood sugar is really high the body overcompensates by releasing a lot of insulin and we get a subsequent drop in blood sugar below the baseline starting point. Protein
Proteins are the essential building blocks, they are crucial in the rebuilding and recovery process but dietary protein does not actually build muscle as a lot of people are led to believe. It is the stimulus of exercise (specifically resistance exercise) that build muscles.
A protein is composed of individual amino acids that your body uses to manufacture, repair, and maintain muscle tissue. Most protein sources come from animals but there are some plant derived ones. There are 20 amino acids that make up various proteins, and humans can produce 10 of these 20 amino acids. The 10 (or depending on the source 8 to 9) essential amino acids must be obtained by food.
Animal proteins contain a high amount of essential amino acids. Plant proteins however are low in one or more amino acids - this is called the limiting amino acid. Vegetarians need to put some thought into their food choices so they get complete proteins - when two or more proteins combine to compensate for the deficiencies in amino acid content in each protein. Like carbs, proteins provide four calories per gram.
Fats
As we are well aware dietary fats has been given a lot of bad press (the reason we see so many no fat, fat free, half fat products) now carbohydrates are receiving bad press! Fat has been misunderstood and was thought to be detrimental to performance, health and cause weight gain.
Science is now realising that fats (good ones) play an important role within the body and actually play a crucial role in health and performance. The body does need fat to survive and some fats are essential to life.
Fats are the most concentrated source of energy packing nine calories per gram.
Our cells are surrounded by a fatty layer and are the base foundation of our whole bodies. All our systems, cardiovascular, musculoskeletal, respiratory, etc are comprised of cells and we need this fatty layer intact to provide optimal cell health which then will provide optimal system health.
The bad press stemmed from us eating too much and the wrong kinds of fats. The three types of fats are saturated, monounsaturated, and polyunsaturated. There is another fat "hydrogenated" that is a product of science and should be completely avoided.
Saturated fats are are solid at room temperature and come from animal products and some tropical oils (coconut, palm, palm kernel and others). The body has to convert the solid fats into a liquid medium to be transported in the blood. The result is elevated LDL's or low density lipoproteins (bad cholesterol) circulating in your blood stream. You don't want this!
Monounsaturated fats are liquid a room temperature and come from olive oil, canola, avocados, nuts, seeds and cold water fish. These fats contain the so-called essential fatty acids, Omega-3's and Omega-6's.
The western diet at large seems to be devoid of Omega-3's which are found in cold water fish such as salmon, trout, sardines, herring etc and in excess of both saturated and Omega-6 fatty acids.
An imbalance between Omega-3 and Omega-6 ratio could be deleterious to our health. Omega-3's are super beneficial to heart health, aiding in recovery, anti-inflammatory and reducing the risk of several other diseases. While Omega-6's even though essential, when eaten in majority compared with Omega-3's, stimulate pro-inflammatory pathways in the body. Dominant Omega-6 in the body can create chronic inflammation, cancer, heart disease, stroke, auto immunity among others.
Polyunsaturated fats are also liquid at room temperature and are found in safflower, corn, sunflower, soybean, flax, fish oil and more. Unlike saturated fat, polyunsaturated fat does not raise our cholesterol levels. In fact, polyunsaturated fats lowers our low density lipoprotein (bad cholesterol). However unlike monounsaturated fats, polyunsaturated fats is also believed to lower the the high density lipoprotein (good fats).
The newest guidelines state that an individuals consumption of polyunsaturated fats should not exceed 10% of total caloric intake. Ideally you also want to look for and use Omega-3 polyunsaturates such as flaxseed oil, oily fish, walnuts and pumpkin seeds.
A note on Trans Fats
Trans fats are basically vegetable fats that have been changed chemically by a process known as hydrogenation. The process is done by food manufactures by artificially adding hydrogen to liquid unsaturated fats to give greater stability and longer shelf life. The hydrogenation process makes liquid fats solid at room temperature.
We should avoid Trans fats as much as possible. Why? becuase trans fats not only raise total cholesterol like saturated fats, they also go one step further and deplete our HDL (good cholesterol) which protects against heart disease.
Check you food labels, if you see hydrogenated or partially hydrogenated on the label then the food has some quantity of trans fats. The US, Canada and some european countries have placed mandated labeling requirements for trans fat in foods. Unfortunately Australia and New Zealand have not followed suit. Trans fats are found in, fast foods, donuts, muffins, cookies, crackers, cakes, microwave pop corn and many other foods.
Now that we have a baseline understanding of macronutrients, lets get into nutrition 101 for optimal health and performance.
|
