The effect of lifestyle on some non-communicable diseases: Obesity as a risk factor for Type 2 diabetes.

The idea

Obesity means carrying excess body fat, often assessed using body mass index (BMI = mass in kg ÷ (height in m)²). Type 2 diabetes is a non-communicable disease in which body cells respond poorly to insulin, so blood glucose is less well controlled. Obesity is a major risk factor: excess fat tissue, especially around the abdomen, makes cells less sensitive to insulin and increases the demand for insulin. This raises the chance of developing Type 2 diabetes, but it does not guarantee it, and not everyone with Type 2 diabetes is obese. Risk factors increase probability rather than cause disease directly. Reducing obesity through a balanced diet and regular exercise lowers the risk.

What earns the marks

• Define obesity as excess body fat, commonly indicated by a BMI above the healthy range, and state that it is a lifestyle-related condition.
• Describe Type 2 diabetes as a non-communicable disease where body cells respond less well to insulin, so blood glucose control is reduced.
• Explain the link: excess fat tissue reduces cell sensitivity to insulin and increases insulin demand, raising the risk of developing Type 2 diabetes.
• State that obesity is a risk factor, not a direct cause, so it increases the probability of Type 2 diabetes rather than guaranteeing it.
• Give a concrete example, such as a person with a high BMI and low activity level having a greater risk than someone with a healthy BMI.
• Suggest that losing excess body fat through diet and exercise can reduce the risk of developing Type 2 diabetes.

Common mistakes and how to put them right

• Confusing Type 1 and Type 2 diabetes.

  Put it right: Link obesity specifically to Type 2 diabetes.

• Claiming that obesity always causes Type 2 diabetes.

  Put it right: Describe obesity as a risk factor that increases the chance of developing the disease.

• Writing that obesity directly destroys insulin-producing cells.

  Put it right: Explain that obesity mainly reduces the sensitivity of body cells to insulin, increasing insulin demand.

Exam tips

• Use the phrase risk factor and explain that it increases the probability of disease rather than causing it directly.
• Link the biology clearly: excess fat → reduced insulin sensitivity → poorer blood glucose control → increased risk of Type 2 diabetes.
• Include a named lifestyle measure, such as regular exercise or a balanced diet, that can reduce obesity and therefore lower the risk.