Glossary
Starting with A for "ACE inhibitor" and continuing through to Y for "Yolk Sac Tumour", we give you succinct explanations for scientific and medical terms in clear and simple words.
- OverweightDefinition
Individuals suffering from overweight have a raised proportion of body fat. In its wider sense, overweight means a body weight which is above the normal value. Depending on the extent, the World Health Organisation (WHO) distinguishes between overweight, marked overweight (obesity) and extreme overweight (morbid obesity). Overweight in the wider sense is the most frequent form of malnutrition in western industrial countries and is regarded as a risk factor for numerous secondary diseases, such as type 2 diabetes, high blood pressure (hypertension), raised blood cholesterol values (hypercholesterolaemia), hyperlipidaemia, metabolic syndrome, vascular diseases (particularly arteriosclerosis), joint diseases (arthrosis) and sleep apnoea syndrome. Overweight also has an unfavourable effect on diseases which are already present. Studies have shown that pathological overweight increases the risk of death.
Causes
Overweight can often be shown to be caused by several factors. Disturbances in the feeling of satiety, family traditions in eating, social environment, psyche, a sedentary way of life, the choice of unhealthy energy rich food and low levels of exercise all support the development of overweight. Metabolism and genetic factors often interact with the way of life in influencing the development of overweight. In 20% of individuals with pathological overweight, the energy turnover is reduced as a result of, for example, low thyroid function, brain disease or intake of certain drugs.
Symptoms
Overweight is characterised by an increase in the proportion of body fat. In women of normal weight this is ca. 20-25% of total weight and in men ca. 15-18%.
Diagnosis
A value can be calculated on the basis of the formula for body-mass index (abbreviation BMI) with the help of which it can be recognised whether and to what extent overweight is present. The BMI is calculated from the body weight (kg) divided by the square of the height (m2). According to the WHO classification of BMI, a person with a BMI of from 25.0 to 29.9 kg/m2 has overweight (Class 1), with a BMI of from 30.0 to 39.9 kg/m2 is suffering from obesity or marked overweight (Class 2) and with a BMI of more than 40.0 kg/m2 from so-called morbid obesity or extreme overweight (Class 3). The ratio of hip to waist circumference (waist-hip ratio, abbreviation WHR) is a further parameter and is a measure of the distribution of fat. In men the WHR should be under 1 and in women under 0.8. Higher values suggest that the overweight should be treated, as there is increased risk of metabolic abnormalities and cardiovascular diseases.
Therapy
Pathological overweight should always be treated, as it is a risk for secondary disease. There are few exceptions, such as advanced age. Treatment is urgent if the overweight is already associated with metabolic diseases such as diabetes mellitus, abnormalities in lipid metabolism or other diseases which are unfavourably affected by overweight (e.g. hypertension, orthopaedic conditions, coronary heart disease). The motivation and self-management of the overweight person is essential for the success of the therapy.
Drug therapy
appetite suppressants should only be taken for special medical reasons, as there is the danger of dependence. Conditions for this treatment include combination with a low calorie diet, behavioural therapy and exercise, a BMI of more than 30 kg/m2 and the demonstration of disease which is unfavourably affected by the overweight. Lipase inhibitors decrease the uptake of fat from food.
Operative Therapy
Operations are only carried out on persons with clearly pathological overweight, i.e. with a BMI of more than 40 kg/m2 or with a BMI of more than 35 kg/m2 with the simultaneous presence of diseases which are unfavourably affected by the overweight. The pathological overweight must have been present for at least five years and not be caused by hormonal abnormalities. Several courses of weight reduction must have been performed before the operation.
Operations should not be carried out on individuals with underlying psychiatric disease, alcoholism or when the risk of the operation is high.
During the operation a so-called gastroplasty is inserted. The resulting reduction in gastric volume causes a more rapid feeling of fullness or satiety. Strict diet is necessary even after the operation, to avoid vomiting after excessive food intake and to achieve effective weight reduction. The expected reduction in weight is between 30 and 70 kg. This treatment may fail if large quantities of highly calorific drinks, mushy food or alcohol are ingested. Secondary operations are often necessary after massive weight (for instance, of the abdominal wall when there is a large apron of fat).
All other operations (bypass in the intestinal area, liposuction of depot fat) are outdated and no longer usual.
Psychotherapy
Behavioural therapeutic measures should be a component of every treatment of marked overweight. Group discussions or psychological care support the loss of weight and, particularly, improve the long term success.
Other Measures
1. Dietetic therapy: If at all possible, dietetic advice should be given by a specially trained dietetic assistant. The decision whether to use a low calorie mixed diet or a very low calorie diet depends on the concomitant diseases, the urgency of the weight loss, the severity of the overweight and the readiness of the overweight person. Diet should be accompanied by physical endurance training if this is not contraindicated. a) low calorie mixed diet: Energy supply depends on the degree of overweight and the activity of the individual. High fat and high sugar foods and alcohol must be reduced. Fruit, vegetables, wholemeal products, mineral water and tea should be favoured. b) very low calorie diet: A medical examination should take place before the start of the treatment and a weekly medical check-up during the treatment is also required. At least 2 l of zero calorie fluid should be drunk each day. Vitamins and perhaps potassium should also be taken. The expected reduction in weight in four weeks is ca. 10 kg in women and 12 kg in men. This form of diet should not be used with, for example, type 2 diabetes with advanced late complications, cardiac defect, heart failure, severe hypertension, advanced arteriosclerosis, cardiac arrythmia, pregnancy, breast feeding, age under 18 or psychiatric disease. Zero diets and all one sided unscientific forms of fasting are outdated.
2. Physical training: Only endurance sports have a positive effect on metabolism, e.g. swimming, cycling, rowing, walking, mild jogging or ski langlauf. Caution is required, because of the danger of excessive stress on the joints and ligaments. Daily walks are recommended for older people. Exclude contraindications (particularly cardiovascular disease) before starting training.
Prevention
Regular check of body weight, balanced nutrition, sport several times weekly or plentiful movement. If there is a tendency to overweight, possible reduction in calorie intake.
Glossary entries: Roche and Walter de Gruyter, Berlin