Depending on who you speak to you will probably be told that these 3 are either brilliant for you or terrible for you as lots of people having looked at various diets have developed their own opinion over the years. The real fact of the matter is that they are both great for you and bad for you, its all about balance. Too little and you could die and too much and you could die, its all about finding that nice spot in between!
Carbohydrates
With the exception of water, this is the largest part of your diet with most sources recommending that you have 300g per day. Carbs are branched macromolecules that are made up of lots of sugar molecules such as glucose, fructose and lactose. Sugar units like these are often referred to as monosaccharides, and when they pair up through a glycosidic bond they form disaccharides. If multiple units join together they create polysaccharides more commonly known as Carbohydrates.
 |
| The monosaccharides Glucose and Fructose |
Why do we need them?
Carbs are broke down into their sugar subunits and are used as a source of energy, so the logic goes that the more carbs you have the more energy you have right? This is not always true but we'll come back to that! The fact is though, if you don't have enough carbs then you will feel tired or sluggish because your not managing your diet right, hence why you will hear people saying "my blood sugar is low", this is in essence correct, so its time for a snack!
Where do they go?
As mentioned before, carbs are broken down into sugar, but this isn't the end of the process. Your body doesn't want your blood sugar to go through the roof every time that you eat so it uses the hormone insulin to convert all this excess sugar into glucagon. This is then stored in the muscles (~400g) and in the liver (~100g).
The glucagon stored in the muscles are used for fuel in muscle contractions, and the glucagon in the liver is used to maintain the blood glucose level so that all other areas of the body has access to energy. You may have noticed though that the muscles and liver have a limit on the amount that they can store, so what happens to the rest? This is where the issues on over indulging on carbs comes, the excess is stored as fat in the adipose tissue in the body. This is why if you eat too many sweets you get fat!
The lesson is to regulate your carb intake, you should eat low GI foods (Glycemetric Index) such as wholemeal bread and pasta as they are digested slowly and prevent large spikes in blood sugars. On days when you are being active it is fine to eat foods with high GI values such as white bread and chocolate, as it will give you a quick boost in sugar allowing you to compete at a high level!
Protein
As with carbohydrates, protein are larger structures that are made up of lots of small subunits, in this case the subunits are amino acids, of which there are 20 natural ones, and many unnatural versions. Our bodies are unable to make the natural ones so we need to get them exclusively from our diet.
 |
| Generic Amino Acid - R is variable |
Why do we need them?
Protein has a variety of uses, they repair and build new tissues and cells, they are used for making hormones and antibodies and in a pinch they can be used as a source of energy.
For an athlete the key feature of proteins are their ability to repair tissues. Our bodies are in a continual process of breaking down tissues and rebuilding them. When we exercise we damage our muscles, causing the need for our body to repair them (this is why you feel sore the day after a gym session), protein is used to repair these muscles, and in the process they make them bigger. So it doesn't matter how much exercise you do if you don't have enough protein in your diet you won't get positive results!
Where do they go?
Unfortunately we don't store protein for long, the body instead metabolises it to form urea and it is expelled from the body. This means that you can't just overload on protein at the start of the week and expect that to be good enough. Daily control of your protein intake is required to get decent results, so once again the answer is a balanced diet!
Fat
Fat comes in 3 main forms, saturated fat, unsaturated fat and trans fat. Saturated fats and trans fats should be largly avoided as they have been associated with heart disease and other health problems, where as unsaturated fats are deemed the healthier option though should only be a maximum of 30% of you dietary calorie intake! As a whole fats are made of triglycerides, which are units that contain a glycerol unit and 3 fatty acids.
 |
| the unit on the left is the glycerol attached to 3 fatty acid chains |
Why do we need them?
Fat is one of the nutrients that has a really bad reputation in recent years, in the past people thought it was brilliant as it had lots of benefits and being larger was good because it kept you warm in the winter. These days people use fat as the whipping boy for health problems, but most people don't realise how useful fat is. As well as providing insulation to keep us warm, fat also makes up cell membranes, nerve sheaths, bone marrow and surprisingly contributes to 60% of the human brain!
There are also some vitamins that are fat soluble and use fat as a medium by which then can be absorbed by the body. In terms of exercise fat can also be used as an energy source, with 1g providing the body with 9kcal of energy (protein and carbs only give is 4kcal / g). This however is less readily available so we can't use it in explosive actions like sprinting or weight lifting, instead it gets utilised during endurance events like running or cycling.
Where do they go?
Fat is stored in the adipose tissue which is found below the skin, around the organs (visceral fat) and in the bone marrow. Men tend to find that they but fat on around the stomach area (apple shaped bodies) where as women tend to put it on the legs and bums (pear shaped bodies).
Visceral fat is the worst of the 3, as this it the kind that is associated with health problems such as heart conditions. Most fat around the stomach is visceral fat, so if you have a large belly you need to change your diet and do more exercise or you run the risk of having severe health problems! This also helps to explain why heart problems tend to effect men more then women!
Well thats everything on nutrients for now, if you have any questions leave me a comment below!
Thanks,
Rich
References:
No comments:
Post a Comment