9 min readConcept sheetPart II (2 marks) on the symptoms of diabetes; Part III (4 marks) on obesity or heart disease; Part IV (7 marks) on lifestyle diseases

Lifestyle diseases: obesity, diabetes and heart disease

Unhealthy food, little exercise, stress and smoking cause lifestyle diseases like obesity, diabetes and heart disease. A balanced diet and regular exercise prevent them.

BMIBody mass index = weight (kg) ÷ [height (m)]²

Obese (WHO cut-offs for adults)BMI of 30 or more; overweight is 25 to 29.9

Diabetes mellitusHigh blood glucose because insulin is lacking or does not work well

Blood pressure (WHO)Normal about 120/80 mm Hg; 140/90 mm Hg or more is hypertension

What are lifestyle diseases?

Lifestyle diseases are non-infectious diseases caused mainly by the way we live. They do not spread from person to person. Causes include too much fried, sugary and junk food, sitting for long hours and too little exercise. Stress, smoking and alcohol add to the risk. These diseases develop slowly over years. The main ones are obesity, type 2 diabetes, high blood pressure and heart disease.

Worked example: finding BMI

Problem

Ravi weighs 81 kg and is 1.8 m tall. Find his BMI and say which group he is in.

Working

Formula: BMI = weight (kg) ÷ [height (m)]²
Height² = 1.8 m × 1.8 m = 3.24 m²
BMI = 81 kg ÷ 3.24 m² = 25 kg/m²
WHO groups for adults: below 18.5 underweight; 18.5 to 24.9 normal; 25 to 29.9 overweight; 30 or more obese.

Answer

BMI = 25 kg/m², so Ravi, an adult, is in the overweight group by the WHO cut-offs.

Obesity

Obesity is too much body fat, enough to harm health.
The BMI cut-offs in this unit are the WHO cut-offs for adults. For children and teenagers, doctors compare BMI with growth charts for age and sex. Doctors in India often use lower cut-offs for Asian adults.
Causes: overeating, junk food, a sedentary (inactive) life, family genes and hormone problems such as low thyroid hormone.
Effects: high blood pressure, type 2 diabetes, heart disease, joint pain and breathing trouble during sleep.
Prevention: a balanced diet with vegetables, fruits and whole grains, and less sugar and fried food. WHO advises children and teenagers to get about 60 minutes of physical activity a day.

Type 1 vs type 2 diabetes

Type 1 (insulin-dependent)The pancreas makes little or no insulin, because the body's immune system destroys its beta cells. It usually starts in children and young people. It is treated with insulin injections.

Type 2 (non-insulin-dependent)Insulin is made, but body cells do not respond to it well (insulin resistance). It is mostly seen in adults and is linked to obesity and inactivity. It is controlled by diet, exercise and tablets, and sometimes insulin.

Common symptoms of both: polyuria (passing urine often), polydipsia (great thirst), polyphagia (great hunger), glucose in the urine, tiredness and slow healing of wounds.

Heart disease (coronary heart disease)

Atherosclerosis: fat and cholesterol build up as plaque inside the coronary arteries, which supply the heart muscle. The arteries become narrow.
Less blood reaches the heart muscle. This causes chest pain called angina.
If an artery is fully blocked, part of the heart muscle dies. This is a heart attack (myocardial infarction).
Hypertension (by WHO, blood pressure that stays at 140/90 mm Hg or more) strains the heart. Normal blood pressure is about 120/80 mm Hg.
Risk factors: smoking, fatty food, obesity, diabetes, stress, inactivity and family history.
Prevention: less oil, salt and sugar; regular exercise; no smoking; yoga to control stress; regular check-ups.

In real life

Swap fried snacks and sweet drinks for fruit, sundal and buttermilk, and play outdoors for an hour daily. These habits protect you from obesity and type 2 diabetes.

Exam angle

2 marks: “Write any two symptoms of diabetes mellitus.” Polyuria (passing urine often), polydipsia (great thirst), polyphagia (great hunger), glucose in the urine.

4 marks: “Distinguish between type 1 and type 2 diabetes.” Type 1: no insulin made (beta cells destroyed), young people, insulin injections. Type 2: insulin resistance, adults, linked to obesity, controlled by diet, exercise and tablets.

7 marks: “What are lifestyle diseases? Explain obesity, diabetes and heart disease with their prevention.” Define; obesity (BMI, causes, effects); diabetes (types, symptoms); heart disease (atherosclerosis, angina, heart attack, hypertension); prevention by diet, exercise, no smoking, check-ups.

Remember it

Diabetes has three Ps: Polyuria, Polydipsia, Polyphagia.