Diabetes type 1 usually affects younger people (which is why type 2 diabetes is also called "old age diabetes"). Younger here means around 40 or below. Other names for type 1 diabetes are insulin dependent diabetes (IDDM where the M is short for Mellitus) and juvenile diabetes.

What causes diabetes type 1?

Diabetes type 1 means that your body no longer produces (enough of) insulin which is necessary for the body to use glucose (the last step in the digestion) properly.

The reason your body stops producing insulin if you have IDDM is that the beta cells in the pancreas have been attacked by your own body's immune defence and been destroyed. Without these essential beta cells, your pancreas can no longer produce insulin and without it, the glucose from your food tends to stay in the bloodstream instead of being transported to the cells as energy. The starving cells will then grab the energy from your body fat which explains your weight loss.

Burning fat in a large scale like this also makes the body produce a class of acids called ketones (hence the odeur of acetone). Indicentally, this is also the much debated side effect of the Atkins diet - where you (according to Atkins) trick your body into using the body fat by having a large amount of protein in your diet. This has never been proven though in the Atkins case.

With a large amount of ketones in your body, there is a risk of a complication called ketoacidosis which is a potentially life threatinging condition.