Obesity is a state in which there is generalised accumulation of excess adipose tissue in the body leading to more than 20%of the desirable weight. Obesity invites disabilty, disease and premature d eath. Excess body weight is a hindrance, leading to breathlessness on moderate exertion and predisposes a person to diseases like atherosclerosis, high blood pressure, stroke, diabetes, gall bladder diseases and osteoarthiritis of weight bearing joint and varicose veins.
ETIOLOGY–
1.Genetic factors–
Genetic inheritance probably
influences 50-70 % a person chance of becoming fat more than any other factor.A genetic base regulate species differences in body fat and sexual diffrences within a species.Within families the chance is 80 %if both parents are obese,only 10%if niether parent is obese.A mutation for the human gene for the b3 recepterin adipose tissue, involved in lipolysin and thermogenesis markedly increase the risk of obesity
2. Age and Sex–
It can occur at any age in either sex as long as the person is under positive energy balance.
3. Eating Habits–
Certain eating habits may lead to obesity-
(a). Nibbling between meals is common among housewives and is a potential cause for obesity.
(b). Some may eat faster taking less time for chewing, therefore they tend to consume more food.
(c). Obese persons respond to external cues to eat rapid and internal hunger signals. They eat when it is meal time or when they are surrounded by tasty food instead of when they are hungry.
(d). Housewives who are fond of cooking variety of food or persons who are working in the kitchens may become obese.
(e). Business executives who frequently attend business lunches have more chances of becoming obese.
(f). Housewives who do not want left over food to be thrownout may consume forcibly and put on weight.
(g). Some persons eat more food when they are unhappy as a compensation mechanism.
4. Physical Activity–
Obesity is found in persons who lead a sedantry lives and pay less importance to physical activity. Though obesity can occur at any age, this is more common during middle age when physical activity decreases without corresponding decrease in food consumption.
5. Endocrine Factors–
Obesity is found in hypothyroidism, hypogonadism and Cushing?s syndrome. Obesity is common at puberty, pregnancy and menopause, suggesting endocrine may be a factor in obesity.
6. Trauma–
Obesity may follow due to damage to the hypothalamus after head injury because it is not able to regulate appetite or satiety.
7. Prosperity–
Obesity is common in prosperous countries like UK, USSR and USA and people from higher socio- economic status of developing countries. They have the purchasing power and availability of surplus food. Obesity is rare in primitive societies and wild animals. Civilisation has brought plentiful supply of appetising foods, concentraed food and variety of foods in the market.
Crash diets, gimmicky fads and schemesmay cause temporary weight loss due to an increase in eating awareness and a forced change in habits, yet any results are impermanent. As soon as the diet is forsaken, any lost weight is regained- usually with additional poundage. Long term weight control requires a permanent sense of awareness and lifelong habit change. Only temporary weight loss and certain undesirable side effects will be accompalished with erratic bursts of drastic caloric restriction.
Focus should be on non-weight goals such as improved health and fitness, and incresed self esteem. Success is more likely when goals are reasonable and allow for a gradual adjustment in life style.
Theories-
Fat Cell Theory-
The number of fat cells are determined early in life to provide space to store fat. Once they have been found, fat cells have a tendency to remain full of fat. Total number of fat cells are set early in life, supporting the notion that juvenile onset obesity was caused by an increase in the number of fat cells while adult onset is caused by increase in the size of fat cells. The number of fat cells can increase in adult life and that the number of fat cells also actually diminish as the result of sustained weight loss. People with a large number of fat cell have more difficulty in loosing body weight than those with fewer fat cells.
Set Point Theory–
Each person has an ideal biological weight or set point, once body weight reaches this point, a whole set of signals is produced that influences the person?s food intake to maintain this weight. Research has shown that risk for medical problems is related to the size of the fat cells presence more than the number of fat cells or the person?s weight.