Minor variations from the mean do not warrant investigation, but if the height of an individual falls below the third centile (3 per cent of normal children have a height that falls below the third centile) or above the 97th centile, investigation is required. Changes in the rate of growth are also important, and skeletal proportions may provide useful information. There are many children who are normal but who are small in relation to their parents; the problem is merely growth delay. These children take longer to reach maturity and there is also a proportional delay in their skeletal maturation – so that the actual height must always be assessed in relation to maturity. The change in skeletal proportions is one manifestation of maturity, but other features include the maturing of facial features with the growth of nose and jaw, and dental development. Maturity of bone can readily be measured by the radiological bone age.
Failure to gain weight is of more signi?cance. Whilst this may be due to some underlying disease, the most common cause is a diet containing inadequate calories (see CALORIE). Over the last six decades or so there has been quite a striking increase in the heights and weights of European children, with manufacturers of children’s clothing, shoes and furniture having to increase the size of their products. Growth is now completed at 20–21 years, compared with 25 at the turn of the century. It has been suggested that this increase, and earlier maturation, have been due to a combination of genetic mixing as a result of population movements, with the whole range of improvement in environmental hygiene – and not merely to better nutrition.
In the case of adults, views have changed in recent years concerning ‘ideal’ weight. Life-insurance statistics have shown that maximal life expectancy is obtained if the average weight at 25–30 years is maintained throughout the rest of life. These insurance statistics also suggest that it is of advantage to be slightly over the average weight before the age of 30 years; to be of average weight after the age of 40; and to be underweight from ages 30–40. In the past it has been usual, in assessing the signi?cance of an adult’s weight, to allow a 10 per cent range on either side of normal for variations in body-build. A closer correlation has been found between thoracic and abdominal measurements and weight.... weight and height
Weight loss or weight gain occurs if the net balance is disturbed.
Weight can be compared with standardized charts for height, age, and sex. At all ages, divergence from the normal weight for height may have medical implications. For example, if weight is below 80 per cent of the standard weight for height, the individual’s nutrition is probably inadequate as a result of poor diet or disease, and if 20 per cent above the standard, he or she is considered to be suffering from obesity. An alternative method of assessment is use of the body mass index (, or Quetelet’s index), obtained by dividing weight in kilograms by the square of height in metres. A healthy weight is 20–25 ; a of greater than 25 indicates that a person is overweight. weight loss This occurs any time there is a decrease in energy intake compared with energy expenditure. The decrease may be due to deliberate weight reduction or a change in diet or activity level. It may also be a symptom of a disorder. Unexplained weight loss should always be investigated by a doctor.
Many diseases disrupt the appetite, which may lead to weight loss. Depression reduces the motivation to eat, peptic ulcer causes pain and possible food avoidance, and some kidney disorders cause loss of appetite due to the effect of uraemia. In anorexia nervosa and bulimia, complex psychological factors affect an individual’s eating pattern.
Digestive disorders, such as gastroenteritis, lead to weight loss through vomiting. Cancer of the oesophagus (see oesophagus, cancer of) and stomach cancer cause loss of weight, as does malabsorption of nutrients in certain disorders of the intestine or pancreas.
Some disorders cause weight loss by increasing the rate of metabolic activity in cells. Examples are any type of cancer, chronic infection such as tuberculosis, and hyperthyroidism. Untreated diabetes mellitus also causes weight loss due to a number of factors.... weight
The most efficient way to lose weight is to eat 500–1,000 kcal (2,100–4,200 kJ) a day less than the body’s total energy requirements. Exercise also forms an extremely important part of a reducing regime, burning excess energy and improving muscle tone.
In most circumstances, drugs play little part in a weight loss programme.
However, sibutramine and orlistat may be useful adjuncts to a reducing diet and may be appropriate for some people with a high (see body mass index). Appetite suppressants related to amfetamines are not recommended.... weight reduction
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