Obesity is a condition in which the individual is overweight due to deposition of fat in the adipose tissue. The common cause of obesity is consumption of food in excess of requirements. Excess food consumed is converted into fat and stored in the adipose tissues. Obesity is very common among people living in Western countries and among the higher income groups in India and other developing countries.
Aetiology and occurrence:
Many factors contribute to the development of obesity. Some of these are discussed below:
Age and Sex: – Obesity can occur at any age in either sex. The incidence is higher in persons who lead sedentary lives.
Economic status:-Obesity is more common among the higher income groups as they consume excess food and do less physical work than the low income groups.
Physical activity:- Obesity occurs rarely among persons who do hard physical work. It is very common in those who lead sedentary lives. With the extensive use of transport facilities and mechanization of industry, the proportion of people who lead sedentary lives has been increasing.
Proneness to obesity:- Some individuals are more prone to develop obesity than others. Recent investigations have shown that these individuals have usually large proportion of adipose tissue cells as compared with normal persons. These cells are filled with fat when excess food is consumed.
Physiological regulation of food intake:-
Food intake is controlled by the central nervous system. It is initiated by hunger and inhibited by feeling of fullness of the stomach. Food intake is markedly influenced by the feeding centre and satiety centre present in the hypothalamus region in the brain. In experimental animals, if the feeding centre is destroyed, the animals lose appetite, refuse to eat and finally die of starvation. If the satiety centre is destroyed the animals eat voraciously and become obese in a short time.
Assessment of obesity:-
Obesity can be assessed by:-
(i) Body weight
(ii) Estimation of total body fat and
(iii) Skin-fold measurement.
A person whose body weight is higher than normal by 20 percent may be considered as obese. An approximate classification of different degrees of obesity based on body weight is giver below:
Body weight excess Degree of obesity
50 Very severe
Complications of obesity:-
Obesity leads to the development of several complications such as:-
Proneness to accidents and
Low life expectancy.
Obese persons suffer more often from metabolic disorders such as diabetes mellitus, atheroscleroses and heart diseases. They meet with accidents more frequently. The life expectancy is also reduced in view of the above hazards.
Treatment: – Since obesity is caused by excess calorie intake and lack of exercise, the main principles involved in the treatment are:
(i) Reduced calorie intake and
(ii) Increased physical activity.
Reducing diet:- The aim of reducing calorie intake is to produce a calorie deficiency in the body which will result in utilization of fat stored in the adipose tissue to meet the calorie needs. A reducing diet should normally provide only about half the daily calorie requirements.
Exercise:– Moderate exercise will help to expend more energy and prevent increase in body weight in normal persons consuming diets just adequate in calories. For example, walking 3 miles a day will require 300 Kcal.
Obesity can be prevented by avoiding excessive and frequent eating of foods rich in calories, uiz . Fried foods, nuts, sweets, etc. and by taking mild to moderate exercise daily. The body weight should be maintained constant at the normal level by adjusting the calorie intake. Nutrition education of children and of prevents the present widespread occurrence of obesity.