Type 1 and Type 2 diabetesSpec 4.5.3.2
In short
Type 1 diabetes is a disorder in which the pancreas fails to produce sufficient insulin, causing uncontrolled high blood glucose levels. It is normally treated with insulin injections. In Type 2 diabetes the body cells no longer respond to the insulin produced by the pancreas. Treatments are a carbohydrate controlled diet and an exercise regime; obesity is a risk factor.
Type 1 diabetes is a disorder in which the pancreas fails to produce sufficient insulin. It is characterised by uncontrolled high blood glucose levels and is normally treated with insulin injections.
In Type 2 diabetes the body cells no longer respond to insulin produced by the pancreas. A carbohydrate controlled diet and an exercise regime are common treatments. Obesity is a risk factor for Type 2 diabetes.
| Type 1 | Type 2 | |
|---|---|---|
| Cause | Pancreas fails to produce sufficient insulin | Body cells no longer respond to the insulin produced by the pancreas |
| Blood glucose | Uncontrolled high levels | High levels |
| Treatment | Insulin injections | Carbohydrate controlled diet and an exercise regime |
| Link to obesity | – | Obesity is a risk factor |
Interpreting graphs
You may be given graphs showing blood glucose over time for a person with diabetes and a person without. In a person without diabetes, blood glucose rises after a meal and then falls back to the normal level as insulin is released. In a person with Type 1 diabetes who has not taken insulin, the glucose rises higher and stays high or falls much more slowly. If insulin is injected, the glucose falls.
Reading a glucose graph
One hour after a meal, blood glucose was 9 units in a person without diabetes and 15 units in a person with untreated Type 1 diabetes. Two hours after the meal the values were 5 units and 13 units. Compare how the two people’s blood glucose changed.
- Find the change for each person: without diabetes 9 → 5, a fall of 4 units; Type 1 15 → 13, a fall of 2 units.
- The person without diabetes ends back at the normal level; the person with diabetes remains high.
- Explain: the person without diabetes makes enough insulin, so glucose moves into cells and is stored as glycogen. The person with Type 1 diabetes does not make enough insulin.
Answer: Both fell, but the person without diabetes fell more and returned to a lower level because their pancreas produces insulin. The person with Type 1 diabetes stayed high.
When comparing, name both types in each sentence. ‘Type 1: pancreas fails to produce enough insulin. Type 2: cells no longer respond to insulin.’ Quote figures from the graph to support what you say.
Obesity increases the risk of Type 2 diabetes, so questions may ask you to evaluate information on obesity and diabetes and make recommendations. Think about social and ethical issues as well as the science, for example the cost to health services and whether people should be encouraged to change their diet.
Written and checked against the AQA GCSE Biology (8461) specification · Updated October 2026