Causes of diabetes

Explanation of Food, Insulin, Sugar and Diabetes

Causes of diabetes

The causes of Type 1 diabetes are not fully understood - they are thought to be linked to an immune reaction.
Type 2 diabetes has been shown to be linked to lifestyle factors such as being overweight (especially around the middle), having low levels of physical activity, having an unhealthy diet (such as eating too much or eating foods that are high in saturated fats).  Other things that increase the risk of Type 2 diabetes are genetics (having a family history of Type 2 diabetes; certain cultural groups have higher rates of diabetes such as South Asians or Pacific Islanders), getting older and stress and depression also increase the risk.
To understand diabetes, we need to understand where glucose comes from, and what happens to glucose in our body.
Glucose is a type of sugar which comes from all types of foods

What is your answer to this question:

Where does the sugar/glucose come from in our blood? 

Does it come ONLY from eating sweet food?

The answer is ‘NO’.

Glucose in our body is a type of sugar which comes from all types of carbohydrate in foods.


All carbohydrate in food that we eat (such as fruit, burgers, fish, rice etc.) will be broken down into sugar by our digestive system.

The body then breaks down all of the sugars and starches (carbohydrates) into glucose, which is the basic energy fuel for all cells in the body.

Glucose is a very simple sugar. It is transported to each cell in the whole body via the bloodstream.


All our body cells use glucose as their primary source of energy (for example, our brains, liver and muscles). When glucose builds up in the bloodstream, sometimes instead of going into cells, it remains in the blood. When this happens, diabetes develops and other related complications are also often seen.


  1. Rizwana Kousar 2010. What is Diabetes? Diabetes and Your Community Education Series, Melbourne. © Australian Community Centre for Diabetes (ACCD).
  2. Eleanor Noss Whitney, Corinne Balog Cataldo and Sharon RadyRolfes, 2002, Understanding Normal And Clinical Nutrition6th Edition.
  3. Arthur C. Guyton and John E. Hall, 2006, Text Book of Medical Physiology11th Edition.
  4. Mark L. Wahlqvist, 2002 Australia and New Zealand Food & Nutrition 2nd edition.
  5. Diagrams: Margaret Mayhew, Australian Community Centre for Diabetes (ACCD), 2011.


Did you know?

Diabetes is serious.

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Australian Community Centre for Diabetes Victoria university - Melbourne Australia

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The Australian Community Centre for Diabetes would like to acknowledge and pay respect to the traditional owners of the land you are on.