Obesity

What is Obesity?

Obesity is common in North America, Australia and Europe. It also occurs, but is less common, in developing countries.

Obesity is a chronic disease that is increasing in prevalence and that poses a serious risk for the development of various diseases, like diabetes mellitus, hypertension, heart disease, gall bladder disease and certain forms of cancer.

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Obesity in India

In the urban population of India, refined wheat and rice have virtually displaced coarse grains and millets as the staple cereal, resulting in a substantial reduction in fibre content in the diet and possibly, also the content of micronutrients such as vitamin B-complex, zinc and chromium, etc. As the population ascends the socio-economic scale, cereal intake declines and the intake of sugar and fats generally increase. Convenience and fast foods find increasing acceptance, especially in the context of globalisation.

While a third of India’s population still falls below the poverty line, there has been a steady growth of the relatively affluent urban middle class, now estimated to number over 200 million. Those who have achieved affluence within a lifetime constitute a good proportion of this middle class.

The Nutrition Foundation of India has just completed a study of the prevalence of obesity in urban Delhi.

It would appear from the results of this study that nearly a third of the males and more than half of females belonging to what may be termed the ‘upper middle class’ in India are currently overweight (BMI>25). The prevalence of abdominal obesity in this group is even higher. Assuming that the ‘upper middle class’ in India number around 100 million (half the number of middle class), it may be computed that there are roughly 40 to 50 million overweight subjects belonging to the upper middle class in the country today. If present trends continue, the situation can get worse within a decade, and overweight could emerge as the single most important public health problem in adults. Overweight/obesity may not be considered as a specific disease but it is certainly the mother of important degenerative diseases in adult life. Prevention and control of this problem must, therefore, claim priority attention.

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Causes of Obesity

• Genetic factors

Genetic inheritance probably influences a person's chance of becoming fat more than any other factor. These genes enhance the storage of fat when food is limited and cause an increased risk of obesity when food is abundant and energy expenditure is reduced.

• Eating Habits

Certain eating habits of people may lead to obesity.

Nibbling between meals is a potential cause for obesity.

Some people consume food faster, without enough time to chew, therefore tend to consume more food.

Obese people respond to external cues to eat rather than internal hunger signals. They eat when it is mealtime or when they are surrounded by tasty foods instead when they are hungry. People tend to overeat when they are depressed or in order to avoid wastage of food.

• Physical activity

Obesity is found in persons who lead sedentary lives and pay less importance to physical education. Though obesity can occur at any age, this is more common during middle age when physical activity decreases without corresponding decrease in food consumption.

• Endocrine factor

Obesity is found in hyperthyroidism, hypogonadism and Cushing's syndrome.

• Trauma

Obesity may follow due to damage of hypothalamus after head injury because it is not able to regulate appetite or satiety.

• Prosperity and civilisation

Obesity is common in prosperous countries like UK, USA, and in people of the higher economic strata of society, in developing countries.

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Measuring body weight

The desirable body weight is different for different people. Conforming strictly to a printed chart should therefore not be an obsession.

On a more scientific basis, obesity is expressed in terms of body mass index (BMI):

This is calculated in the following way:

BMI= Weight in kilograms/ (Height in meters)²

The BMI can be compared with the following ranges:

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Types/grades of obesity:

People having a Body Mass Index (BMI), more than 25 but less than 29.9. Overweight does not affect their health, they lead a normal health and life expectancy is above normal. They may reduce weight on their own.

Grade II obesity:

The BMI is between 30 and 39.9. Doctors and dieticians should treat these patients.

Although they appear to be in good health, they have reduced tolerance to exercise and with shortness of breath on exertion, they are unduly fatigued. This is due to the burden of increased weight they carry always and reduced capacity of the circulatory and respiratory systems that are handicapped by masses of internal fat and fatty infiltration of muscle. For mechanical and metabolic reasons these patients are at increased risk of diabetes, artheroscelerosis, hypertension, fatty liver, gall bladder diseases, osteo -arthritis, hernias and varicose veins. Mortality rate also increases.

Grade III obesity:

The body mass index is above 40; these patients are in pathetic condition. Their day to day activities are restricted due to their enormous mass and susceptible to diseases mentioned in grade II. They are susceptible to artherosclerosis, prone to accidents and have serious psychological disturbances.

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Obesity and Associated Disorders

Obese people are more likely to have high blood cholesterol levels, this increases the risk of artherosclerosis, a condition in which fatty deposits build up on the inner linings of the arteries. This may contribute to high blood pressure and coronary artery disease. Arterial thrombosis and embolism, which is blockage of a blood vessel by a blood clot, occurs more often in obese people. Obese people are more likely to develop diabetes mellitus .

Certain cancers such as prostrate cancer, breast cancer and cervical cancer are more common. Women who are obese have a greater risk than women who are not obese for cervical cancer, breast cancer or gallbladder cancer. Men and women who are obese have an increased risk for colon cancer or rectal cancer. Men who are obese have an increased risk for prostate cancer.

Excess weight can put strain on the joints, leading to osteoarthritis , especially in the hips and knees.

Sleep apnea, a respiratory disease is also associated with obesity. In sleep apnea, the person stops breathing several times an hour for 10 or more seconds while sleeping. Too much fat in the person’s neck, blocking the airway, especially during sleep could cause this. Sleep apnea can also be caused by a problem in the portion of the brain that controls breathing. People with sleep apnea do not sleep well.

People who are obese are more likely than people who are not obese to have gastroesophageal reflux disease (GERD) of which heartburn is a major symptom.

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