The importance of a healthy digestive system

Posted on April 8, 2019 by

If the eyes are the window to the soul, then the digestive system is the window to good health. The digestive system is the cornerstone between eating and having adequate fuel for the body to thrive.

A healthy digestive system will lead to:

  • Stronger immunity towards illness or infection
  • Clearer skin
  • Healthier hair
  • Better energy levels

If your digestive system isn’t strong you may not be effectively absorbing all the nutrients and energy from the food you are eating. Single ingredient foods in their most natural form are familiar to the body and will be broken down more efficiently. Examples include:

  • Wholegrains and legumes
  • Fruit and vegetables
  • Lean meat and protein
  • Nuts and unsaturated oils

Foods high in saturated fat, fatty meat and convenience foods, high sugar and refined foods with added preservatives and emulsifiers can inhibit digestion and lead to:

  • Stomach discomfort
  • Inflammation
  • Bloating
  • Lethargy

There is lots of information out there saying to cut out or avoid certain food groups, and for those that are sensitive to those foods it can be effective in improving their digestive health.

However, it doesn’t mean it’s the solution for everyone and if it doesn’t cause a problem for you then there is no need to stop eating that food, especially if it’s a healthy choice.


Exercising your digestive system

In the same way you train your muscles to become stronger, you need to give the digestive system a workout and challenge it with high fibre food that will make it work hard and take time to break down and digest.

The more work that machines do to process and refine foods is all less work and activity the digestive system has to do to break food down, and as you know – when you don’t train, you become weak.


What is going on after food has left your plate

Digestion starts in the mouth even before you start to eat, when you salivate and then chew your food to break it up. If you are a fast eater or don’t chew food properly its only partially broken down before swallowing. This might lead to indigestion or stomach discomfort as when the food hits the stomach it is a step behind where it should be in digestion.

Mechanically you can have issues with digestion if you are cramped over when you are eating. Sitting slumped or lying down after eating can inhibit a direct pathway for the food to travel though the digestive system. The stomach needs some room to expand to allow for the influx of food or it will get squashed. After eating, try to stand or stretch out the midsection to facilitate movement through the stomach and intestinal tract to avoid cramps or indigestion.

Small Intestine
The small intestine is where most of the fuel from food is absorbed into the blood stream. The small intestine has a huge surface area with up to 30-40 square meters wrapped up in the small intestine for nutrient uptake into the blood or lymphatic system before making a trip via the liver to clean it all up before the heart delivers it back to the body. Early on in the small intestine is where all the nutrients essential for athletes like glucose, iron, zinc, magnesium and other water soluble vitamins are absorbed. Further down amino acids and fats and fat soluble vitamins are absorbed.

Large Intestine
The large intestine is where the insoluble parts of food, from foods high in fibre, that cannot be broken down are fermented and prepared for removal as a stool bulk. This part has muscles that contract and release around the bulk to keep it moving through the colon, much like how a caterpillar would crawl along. With a very low fibre diet, there is nothing to encourage this movement and the digestive muscle don’t need to work, so any sudden changes to a healthier diet can cause discomfort as it all kicks back into gear. This part of the digestive system is where water is reabsorbed and hydration plays a role, if dehydrated excess fluid will be taken out of the bulk which makes it hard to remove. Good bacteria in this part of the intestine contribute to the fermentation of fibres and protect the intestinal lining. Any course of antibiotics can cause a disruption to this process impacting the frequency or consistency of bowel movements.


Your bowel

It is normal to have one to two bowel movements a day, if not every two days.

It is a good idea to keep an eye on the frequency and type of bowel movements for your own body awareness as it can give an indication of whether your diet is on the right track and if the food you are eating is right for your needs.


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Thank you for the nutrition information – I may unwittingly have been doing it wrong.
Trouble is, doctors refer one to ppl who seem to know less than I already do, about nutrition, so I struggle, experiment, and sometimes get it right.
I’d like to know the name of the person who wrote the article printed in this month’s Masters Swimming “Importance of Timing Your Meals as an Athlete”, and what his/her qualifications are. This si what I’ve been experimenting with. I have been referred to a dietician, who was full of …., and later to a nutritionist, who was considerably more knowledgeable, but could not answer my questions.
No one can answer my questions about craving (particularly carbs) after a perfectly healthy evening meal. It causes a lot of problems.
Thank you
Jane Bradley VMV

    Matthew Greenlaw

    Hi Jane, these articles are written for the benefit of our athletes by the NSWIS dietitian, Sally Walker, and shared online for the wider public and aspiring athletes. All the best,

    Matthew Greenlaw
    Digital @ NSWIS

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