Type 1 and type 2 diabetes

Greg Foot explains the difference between type 1 and type 2 diabetes and the role insulin plays in controlling glucose levels


Diabetes is a condition where the blood glucose levels cannot be controlled by the body. There are two types of diabetes - type 1 and type 2.

Type 1 diabetes

Type 1 diabetes is a disorder in which the pancreas fails to produce enough insulin. This can be detected from an early age. It is characterised by uncontrolled high blood glucose levels and it can be controlled by injecting insulin.

A medical diabetes kit

People with type 1 diabetes have to monitor their blood sugar levels throughout the day. Their levels of physical activity and their diet affect the amount of insulin needed.

They can help to control their blood glucose level by being careful with their diet, and eat foods that will not cause large increases in blood sugar level, and by exercising, which can lower blood glucose levels due to increased respiration in the muscles.

Type 2 diabetes

In type 2 diabetes the person's body cells no longer respond to insulin produced by the pancreas. It is more common in older people. It can be controlled by a carbohydrate controlled diet and an exercise regime. Carbohydrate is digested into glucose, which raises the overall blood glucose level. There is a correlation between rising levels of body mass in the general population and increasing levels of type 2 diabetes.

Body mass index (BMI) is used to show if a person is a healthy mass for their height.

BMI = mass/(height)2

Commonly accepted BMI ranges are:

  1. underweight: under 18.5 kg/m2
  2. normal weight: 18.5 to 25 kg/m2
  3. overweight: 25 to 30 kg/m2
  4. obese: over 30 kg/m2

People who are overweight or obese have an increased risk of developing type 2 diabetes.

Scientific research has also indicated that people who have more weight around their waist are at a higher risk from developing certain illnesses, such as type 2 diabetes, than people who have more weight around their hips. This is determined by calculating waist to hip ratio:

Waist:hip ratio = waist measurement/hip measurement.

A waist:hip ratio of over 0.85 in women and 1 in men is considered an indicator of obesity.

The correlation between obesity and type 2 diabetes

Describe the pattern in this data.

Mean body weight has steadily increased

From approximately 72.5 kg in 1990, to 75.5 kg in 1997 up to just over 77 kg in 2000.

This matches a general increase in the number of people with type 2 diabetes from 1990 to 2000.

For example, the percentage was just below 5 percent in 1990 up to just below 7.5 percent in 2000. This shows an overall increase in 2.5 percent over 10 years.

Tip: Use the labels on the axes to help you describe the relationship between the data in the graphs.