*Disclaimer I can only speak of my experiences with type one. I am NOT a doctor! :)*
What is "Type One Diabetes" you ask? In simple terms, my pancreas can't produce insulin anymore. Nothing I did has caused it; you can't just get it from eating too much sugar ;).
In not so simple terms, it is an autoimmune disease where the immune system attacks the beta cells in the pancreas. The pancreas produces insulin and insulin is what regulates the amount of glucose (sugar) in the blood.
When insulin is not in my system, there is nothing to break down the sugar. Too much sugar in the body (without insulin) creates ketones which are acids that break down fats to use for energy. Too many ketones can lead to ketoacidosis which can possibly lead to a coma or worse. In order to get insulin into the body I have to give injections of it or wear a pump. There is no other way to get insulin in the body (so no, you can't drink it or soak it into your skin, it has to be by injection).
The way my educator explained it is that insulin is like a key that opens doors for glucose to get into the cells. If there aren't any keys, then the glucose builds up which is harmful to the body.
Type One Diabetes isn’t just being unhealthy and needing to eat the right way. It is a constant fight to keep yourself alive. All day. Everyday. No breaks.
Letting your blood sugar get too low or too high could quite literally kill you. You never know what each day holds. One miss calculation of insulin could send your blood sugar plummeting or skyrocketing. It deals with so much more than just "eating right."