B1aL6  Obesity and Malnutrition

Key Words

Arthritis - a painful condition in which the joints start to seize up.

Balanced diet - all the right nutrients for a healthy life.
Blood glucose - amount of glucose in the blood
Blood pressure - the pressure in the blood
Diabetes - a condition in which the pancreas fails to make the hormones glucagon and insulin.
Fit - body is in good order
Joint - where arms and legs bend

Kwashiorkor - a condition caused by sustained malnourishment

Malnutrition - not getting the right nutrients from a balanced diet.
Obese - very overweight.
Slimming programme - a programme devised to help people reduce their weight.

Test Yourself

Homework
Chemistry GCSE
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Grade E

A balanced diet has the right amounts of the following:

  • carbohydrates - these are broken down quickly to give sugar for energy;

  • proteins - needed for growth and repair;

  • fats - needed for cell membranes, and long-term energy;

  • vitamins - small molecules that are needed in small amounts to keep the body working properly;

  • minerals - natural chemical compounds needed in very small amounts but needed to keep the body working properly;

  • fibre - although not digested, fibre is needed to keep the food moving through the digestive system, and is removed when we go to the lavatory;

  • water - essential for all life processes.

Eating too much makes people overweight, because the foods are turned into fat (flib-flob, spare tyres, etc).  A diet of junk food can lead to a range of health problems. 

While being slightly overweight is not likely to be a threat to your health, being seriously overweight is.  Very fat people are often referred to as obese.  Obesity can increase the risk of:

  • arthritis;

  • diabetes;

  • high blood pressure;

  • heart attacks.

It can also cause difficulties for normal day-to-day activities as shown below:

Although we could joke that this man would need to pay double fare so he could sit down, it cannot be pleasant being crushed up so tight in the narrow confines of an aeroplane.

Obesity is a growing health problem in the developed world, especially in the United States of America.  A slimming programme is needed to reduce weight.  In extreme cases, surgery may be needed

In many parts of the world, the opposite to obesity is true.  Some countries are so poor that malnutrition is a major health problem.  The picture shows a child suffering a condition called kwashiorkor (an African word meaning the sickness the baby gets when the new baby comes).

The condition is characterised by:

  • Swelling of the feet.

  • Distended abdomen,

  • Enlarged liver with fatty inclusions

  • Thinning hair

  • Loss of teeth

  • Loss of skin pigment.

  • Dermatitis or irritation of the skin.

Children with kwashiorkor often develop irritability and anorexia.  The body is less able to develop immunity to disease.  Even if the condition is successfully treated, it can lead to physical and mental impairment.

Some people in the developed world are malnourished.  This can arise from:

  • Poverty;

  • Pressure to conform to the elegant (?) body shape of model girls or boys;

  • Bullying

The eating disorder anorexia usually affects girls, but it can affect boys as well.  Often the latter will combine a very limited diet with intensive exercise.

Grade C

The graph below is commonly used by health professionals to show whether people are of a healthy weight:

The body mass index is worked out with the equation:

BMI = weight (kg) ÷ (height (m))2

A person whose height is 1.78 m, and has a weight of 90 kg will have a BMI = 90 ÷ 1.782 = 28.4

Most people have a BMI between 20 and 30.  Above 35, there will be health problems.  Similarly, below 18.5, there will be health problems because you are underweight.

Overweight people may be prescribed a slimming programme.  This has to be done carefully.  Crash dieting rarely helps, and many people get into the trap of yo-yo dieting, where the weight goes up and down.

 

Grade A

Most weight problems occur due to a bad diet.  Fast foods are a particular cause of concern:

  • They are rich in fat;

  • They often are fried in oil that has a lot of trans-fats, which cause very high levels of cholesterol;

  • There is too much salt;

  • The food is often of very poor quality, and may even be unfit for human consumption.

  • There is not very much in the way of vitamins and fibre

Often the people who live on that kind of food have other life-style issues:

  • They may smoke;

  • They may drink excessively;

  • They take little exercise;

  • They may even take recreational drugs.

All of these combined will lead to severe health problems, and a greatly reduced life expectancy.

Too little fibre can cause constipation.  Where there is naturally a high fibre diet, intestinal disorders like appendicitis are almost unknown. 

Salt is vital in our diet, but too much salt leads to high blood pressure, which in turn can lead to strokes - a bleeding in the brain that can cause paralysis, or even death.  Cholesterol is made in the liver from fats.  It's a vital part of many hormones, and cell membranes.  However, excessive cholesterol can lead to arteries becoming choked up; a heart attack can follow.

Some people say that obese people who do not change their life styles should be charged for their hospital treatment.  Some people have conditions that lead to obesity, but for others, it's a life-style choice: too much eating, and too little exercise.  Such life-styles are not sustainable.  There are enough resources for everyone's needs, but not enough for everyone's greed.