Obesity
Obesity has been defined as having a body mass index greater than 30. The body mass index is measured by dividing the weight in kilos by the (height in metres) squared - i.e. kg/m2. A value between 20 and 25 is regarded as normal, and 25-30 is described as overweight. The problem with the definition is that it does not distinguish between muscle and fat, so an added consideration is waist circumference, since this is considered to give an indication of the amount of fat in the abdomen. A waist circumference of greater than 94 centimetres in a man, and 80 centimetres in a woman is raising a warning flag, while greater than 102 centimetres for a man and 88 for a woman is an indication for action. The percentage of people regarded as obese in the Western World has risen steadily over the past three decades (though more so in some countries than others), mainly because a decrease in physical activity has not been matched by a decrease in energy intake - the excess energy gets deposited as fat. While it is true that obesity can be caused by hormonal problems, particularly thyroid failure, and treatment with certain drugs, these are rare causes and most people are overweight because they over-eat and under-exercise. The excuse that they have a low metabolic rate is a myth - the bigger you are the more energy you expend. The reason why we overeat has probably got both genetic and environmental components. The consequences are increased risk of developing high blood pressure (hypertension), heart disease, none insulin-dependent diabetes mellitus, high cholesterol levels, stroke and insulin resistance syndrome (described in this section). Those of us who suffer from obesity can be helped by diet, particularly if supervised by a dietician, sometimes agents to reduce the absorption of fats in our diets, and in extreme cases surgery to reduce the volume of the stomach. Don’t get fat - get fit.
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