Digestion Explained

Cardiff personal trainer, explains how digestion occurs in the body:

Image courtesy of Ben Schonewille at FreeDigitalPhotos.net

Different macronutrients get digested at different speeds, carbohydrates are digested the quickest and fats and proteins are usually slower. The absorption of amino acids, which are the building blocks of protein, varies from 1.3 to 10 grams per hour, for a typical serving of protein that would be 3-4 hours to be absorbed. The rate of absorption of a raw egg is 1.3 grams an hour this is the slowest of all proteins to be digested, Whey protein isolate, which is commonly found in protein drinks and bars gets absorbed at 8-10 grams an hour. There is little known information about the absorption rates of protein from whole foods, such as meat and fish, from anecdotal evidence these proteins would be digested at a rate between that of the raw egg and whey protein isolate.

Fat is the slowest of all macronutrients to be digested and can take anywhere between 1 and 6 hours to be digested, more fat and a larger meal will take longer to be digested. Fat takes so long to be digested because it is not released from the stomach until it can be properly digested. Fat is then either burnt for energy, stored as adipose tissue or forms part of other cells. The rate at which carbohydrates are digested and stored as glycogen (energy stores) in the muscle depends on, the timing of them being eaten, the type of carbohydrate being equal, the amount of carbohydrate eaten and the combination with other nutrients. If carbohydrate is eaten after exercise then it is absorbed up three times quicker, the sooner to exercise the quicker it will be absorbed. For maximum carbohydrate storage it needs to be eaten within 15 minutes of finishing exercise.

Foods with a higher GI will be absorbed quicker, and will cause blood sugar to rise. If carbohydrate is eaten with fat or fibre it will slow down the rate of digestion and keep blood sugar more stable. We will use the knowledge gained to compare the differences between the digestion of an apple and a doughnut. An apple is 80% water, 15% carbohydrate and a small amount of protein and fibre. The apple is broken down in the mouth, when it reaches the stomach the protein is broken down, in the small intestine the carbohydrate is broken down. Now that the digestive processes have finished the body has nutrients to help the body repair and fuel it. Amino acids, which the protein has been broken down into, are sent into a pool to repair cells, carbohydrate is used to fuel our muscles and nervous system. Because the sugar in the apple is fructose or fruit sugar, blood sugar remains relatively level. The apple also contains an abundance of nutrients for the body. Just under the skin of the apple there is half the Vitamin C content of the apple, it also contains calcium, phosphorus, iron, Vitamin A and potassium.

Phytochemicals and flavonoids help fight against cancer and the fibre helps digestive transit. The doughnut however is a different proposition altogether, it is loaded with saturated fat, trans fat and refined sugar. The carbohydrate content will digested in the same parts of the body as the apple, but it will cause a much bigger rise in blood sugar and an ensuing dip. Saturated fat and trans (man made fat) take a different path to digestion than healthy unsaturated fats. They are absorbed through the intestines (rather than through the liver as are healthy fats) and turned into triglycerides the storage form of fat. They are then coated in cholesterol, which raises bad cholesterol LDL, and lower the good HDL. Trans fats are worse again, they raise bad cholesterol, increase the risk of heart disease and cause weight gain even when there is no excess in calories. Although a small amount of trans fats are created in nature the majority of trans fat in our diet comes from processed foods for example cakes, biscuits and pastries, they are used because they prolong the shelf life of products but should be avoided at all costs.

Cardiff personal trainer, Sam O'Sullivan is a nutrition and weight loss Cardiff expert. http://www.SOSpersonaltraining.com

If your looking for 1:1 personal training in Cardiff, a cardiff personal trainer or weight loss classes in Cardiff then be sure to check out the website: http://www.SOSpersonaltraining.com

Article Source: http://EzineArticles.com/expert/Sam_O'Sullivan/583974

Image courtesy of Ben Schonewille at FreeDigitalPhotos.net

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