Obesity and Anorexia

Abstract

Life insurance companies know that people who are within a certain range of ‘desirable’ weight-for-height live longer than those who are above or below this range. Professional athletes or boxers may be overweight as a result of very heavy musculature, but the great majority of overweight people are too fat. Obesity is one of the most important public health problems of our time, since about a third of all adults in the UK are overweight to an extent which causes a measurable decrease in health and longevity.

Anorexia (lack of hunger) is a common accompaniment of many diseases, and is generally of little clinical importance unless it is severe and prolonged. However a condition called ‘anorexia nervosa’ is quite common in teenage girls; the name is misleading, since it is not lack of hunger, but a morbid fear of normal weight gain, which may cause these girls to starve themselves to a point at which life is endangered.

It is commonly supposed that obesity and anorexia are opposite poles of a spectrum of eating disorders: that obese people overeat, that anorectics undereat and that ‘normal’ people eat ‘normally’, but there is little evidence to support this view. Anorexia nervosa often occurs in girls who were rather obese at puberty, and very rarely occurs in boys at any age. The problem is almost always related to emotional adjustment to sexual maturity in women.

Obesity may develop at any age in either sex as a result of many social, physiological or familial influences. In affluent countries, science and technology ensure that adequate supplies of palatable food are available throughout the year, and in these circumstances man, like his domestic pets, tends to become too fat. We still do not understand why, or how, some people manage to regulate energy balance in conditions of abundant food, while others fail to do so.