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SANutritionSyllabus dot point

How do long-term dietary patterns increase or reduce the risk of diet-related disease?

Explain the links between diet and the major diet-related diseases, including cardiovascular disease, type 2 diabetes and some cancers

Long-term dietary patterns influence the risk of cardiovascular disease, type 2 diabetes, obesity and some cancers. Understanding these links lets people modify diet to lower their risk.

Generated by Claude Opus 4.76 min answer

Reviewed by: AI editorial process; not yet individually human-reviewed

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  1. What this dot point is asking
  2. What diet-related disease means
  3. Cardiovascular disease
  4. Type 2 diabetes
  5. Obesity
  6. Some cancers
  7. Reducing risk through diet

What this dot point is asking

You need to define diet-related disease, explain how specific dietary patterns raise or lower the risk of the major conditions, and show how dietary change reduces that risk.

A diet-related disease is a long-term (chronic) condition whose development is influenced by dietary patterns over time. These are usually multifactorial, meaning diet is one risk factor alongside genetics, physical activity, smoking and age. Diet is one of the factors people can change, which is why nutrition focuses on it.

Cardiovascular disease

Cardiovascular disease (CVD) affects the heart and blood vessels and includes heart attack and stroke. A key process is atherosclerosis, the build-up of fatty deposits (plaque) in artery walls that narrows them and restricts blood flow.

Dietary links:

  • Diets high in saturated and trans fats raise blood LDL cholesterol, which contributes to plaque.
  • High salt (sodium) intake raises blood pressure, straining the heart and vessels.
  • Diets high in fibre, fruit, vegetables and unsaturated fats (such as oily fish) lower the risk.

Type 2 diabetes

Type 2 diabetes is a condition where cells become insulin resistant, so blood glucose stays too high. It is strongly linked to being overweight, particularly excess fat around the abdomen.

Dietary links:

  • A long-term positive energy balance with energy-dense, sugary and fatty foods promotes the weight gain that drives insulin resistance.
  • Diets rich in fibre and wholegrains, with controlled portions, help maintain a healthy weight and steadier blood glucose, lowering risk.

Obesity

Obesity is excess body fat that harms health, resulting from a sustained positive energy balance where energy in exceeds energy out. Energy-dense foods high in fat and sugar, large portions and sugary drinks all contribute. Obesity is itself a risk factor for CVD, type 2 diabetes and some cancers, so it links many diet-related diseases together.

Some cancers

Diet is linked to several cancers. High intakes of processed and red meat are associated with bowel cancer, while diets low in fibre, fruit and vegetables raise risk. Excess body fat and high alcohol intake are also linked to certain cancers. Diets rich in plant foods supplying fibre and antioxidants are associated with lower risk.

Reducing risk through diet

Because diet is modifiable, risk can be lowered by:

  • reducing saturated fat, salt, added sugar and alcohol,
  • increasing fibre, fruit, vegetables and wholegrains,
  • matching energy intake to needs to keep a healthy weight.

These match national dietary guidelines and link to the food-selection content in Topic 3.

In short, diet-related diseases such as CVD, type 2 diabetes, obesity and some cancers are shaped by long-term dietary patterns. Diets high in saturated fat, salt, sugar and energy raise risk, while fibre-rich, plant-based, balanced diets lower it, giving people real power to reduce their own risk.

Exam-style practice questions

Practice questions written in the style of SACE Board exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.

2019 SACE Stage 24 marksExplain how a high-energy diet increases the risk of developing diet-related disorders. Refer to two diet-related disorders in your answer.
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Four marks: establish the general mechanism, then apply it to two named disorders (about 2 marks per disorder, including the link to the high-energy diet).

A diet that is consistently high in energy (kilojoules) means energy intake exceeds energy expenditure - a positive energy balance. The excess energy is stored as body fat, leading to overweight and obesity over time.

Disorder 1 - Type 2 diabetes: Excess body fat, especially around the abdomen, makes body cells less responsive to insulin (insulin resistance). Blood glucose stays high because it cannot enter cells properly, which can develop into type 2 diabetes (2 marks).

Disorder 2 - Cardiovascular disease: A high-energy diet is often also high in saturated fat. This raises LDL cholesterol, which builds up as fatty plaque in artery walls (atherosclerosis), narrowing the arteries and raising the risk of heart attack and stroke (2 marks).

2018 SACE Stage 22 marksMany fruit juices are high in sugar and energy. Identify one diet-related disorder associated with high energy intake for children, and explain how overconsumption of fruit juices may increase the risk of this disorder.
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One mark for naming a suitable disorder, up to two for the explanation of the link.

A suitable disorder is overweight/obesity (or type 2 diabetes).

Fruit juices are high in sugar and energy but low in fibre, so they are easy to overconsume and do not make a child feel full. The extra kilojoules from regularly drinking juice add to total energy intake. If this energy is not used up, it is stored as body fat, leading to a positive energy balance and weight gain over time, which raises the risk of obesity and, in turn, type 2 diabetes.