6.6Chapter 6: Nutrition, Health and Movement

Starvation, obesity and health — Alhussan Biology - Stage 8 Revision Notes & Topical Questions

5 min read 8 parts Lesson 6 of 12 2 quizzes

📚 Alhussan Biology - Stage 8 Hub / Topical Revision

0%read

Lesson summary

Biology 6.6 Starvation, obesity and health — Malnutrition and Deficiency Diseases — Alhussan International Academy — Biology (Stages 7–9) notes: Describe the causes and health effects of starvation and obesity and use BMI to assess body mass.Balanced diet — it means eating the ri…

Energy balance
Lack of exercise
Difficulty
High blood pressure
Heart disease
Benefit of weight loss

Part 1 of 6Right food and right amount

Balanced diet

Balanced diet it means eating the right combination of foods and the right amount.

Malnutrition

Malnutrition both too little food and too much food have serious effects on health.

Part 2 of 6Too little food: starvation

Effects

Effects a person becomes thin, muscles waste away, energy is low and deficiency diseases develop.
Starving children do not grow and develop healthily, and starving adults cannot work and become ill.

Causes

Causes crop failure, natural disasters, war and poverty, and it is not a lifestyle choice.

Scale

Scale over 10% of the world's population do not get enough food, over 800 million people are hungry every day and around 9 million people die of starvation each year.

Energy balance

Energy balance when energy used exceeds energy eaten, the body uses up fat and then muscle.

Part 3 of 6Too much food: obesity

Cause

Cause when we eat more than the body needs, the excess is stored as fat, and continued storage leads to obesity.
Over-eating is a lifestyle choice for many people, although the genes inherited also matter.

Lack of exercise

Lack of exercise in many countries few people have physical jobs and most drive rather than walk, yet cheap food is more available than ever.

Scale

Scale globally, more people are obese than starving.

Reversal

Reversal eating less energy or using more through exercise lowers body fat.

Part 4 of 6Health effects of obesity

1Difficulty

Difficulty it is hard for obese people to exercise, and they are often short of breath.

2Diabetes

Diabetes a lot of body fat makes blood sugar levels hard to control, causing tiredness and eventually blindness and even death.

3High blood pressure

High blood pressure it stresses the heart and blood vessels and causes heart disease and strokes.

4Heart disease

Heart disease fatty material builds up in the blood vessels and may cause a heart attack.

5Cancer

Cancer at least 13 different cancers are more common in overweight and obese people.

6Arthritis

Arthritis strain on the skeleton leads to wear and pain in the joints.

7Deficiency diseases

Deficiency diseases fatty, sugary foods are often low in vitamins and minerals.

8Benefit of weight loss

Benefit of weight loss losing weight reduces the risk of almost all the diseases linked to obesity.

Part 5 of 6Body mass index

BMI mass (kg) ÷ height (m)², so the height must be squared.

BMI	Category
Under 18.5	Underweight
18.5 to 24.9	Healthy (normal) weight
25 to 29.9	Overweight
30 to 39.9	Obese
40 or over	Morbidly obese

Risk

Risk being underweight or obese increases the risk of some diseases.

Limitations

BMI is only one measure, and a very muscular athlete may have a high BMI without too much fat.

Other measures

Other measures neck circumference and the waist-to-hip ratio.

Part 6 of 6Prevention and response

Obesity

Obesity eat a balanced diet with less sugar and fat, take regular exercise and balance energy eaten with energy used.

Starvation

Starvation food aid, better farming and a fairer distribution of food.

Public health

Public health food labels, taxes on sugary drinks, school meal standards and campaigns.

Evidence

Evidence a correlation between obesity and disease does not prove cause, because age, genes and income also matter.

Key terms

Term	Meaning
Malnutrition	Poor health from lacking or having too much of a nutrient or of energy.
Starvation	A severe lack of food.
Obese	Having so much body fat that health is affected, BMI of 30 or over.
BMI	Body mass index, mass divided by height squared.
Diabetes	A condition in which blood sugar is hard to control.
Deficiency disease	An illness from a lack of a nutrient.