Starvation
A shortage or complete lack of food leads to starvation. Under such conditions a lack of both energy and nutrients occurs, and the body responds by lowering its metabolic rate. Because many vitamins are stored within the body fat, well fed individuals can suffer short periods of starvation without developing deficiency diseases.
There are two types of energy malnutrition (also termed protein energy malnutrition PEM), these are kwashiorkor and marasmus.
In kwashiorkor the body cannot synthesize the proteins it needs. Body proteins, including blood proteins, are broken down to supply the body with energy. This loss of proteins from the blood increases its water potential. This means that less water is removed from the body tissues into the blood by osmosis, causing the body tissues to swell. The bloated stomach of a starving child with kwashiorkor is caused by this process, as well as a swollen liver. Oedema means tissue swelling through the accumulation of fluid.
What does wasting mean? > Rapid weight loss, or failure to put on weight.
It is a characteristic of acute PEM
What does stunting mean? > An inability to grow in height, and is difficult to reverse.
It is a consequence of chronic PEM
Anorexia nervosa
This is an eating disorder, it ssufferers are 90% female. The causes are complex, but often are linked to underlying psychological distress about groing up and self image. Anorexics reduce theri weight through extreme dieting, and consider themselves to be fat even when they have lost incredible amount sof weight. Hunger is resisted and often extreme exercise regimes are followed. The condition leads to muscle wasting, poor sexual development and cessation of periods. Many die of starvation.
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Obesity
Another form of malnutrition is caused by overeating. Obese people are so defined if they > have a bodyweight 20% or more above the recommended weight for their height.
The Body Mass Index (BMI) is calculated by dividing mass (kg) by height2 (in metres). People are thus categorised:
| BMI | Category |
| < | underweight |
| 20-24 | acceptable |
| 25-30 | overweight |
| > | obese |
- > Coronary heart disease. Due to higher levels of blood cholesterol and higher blood pressure
- > Diabetes. Due to an inability to control the blood sugar levels
- > Cancers of the colon rectum, postrate (men) and uterus cervix and breast (women)
- > Arthritis. Their large body mass poses extra strain on the musculo-skeletal system.
- > Hernias and varicose veins
Details of the impact of obesity and the role of surgical solutions in the USA are found here. Check it out.