The causes of obesity

The obesity is one of the most frequent nutritional disfunctions in the modern word, it is a complex and heterogeneous patology: It seem that there is not , in effect, a typical obese person and a lot of causes can be at the origin of the disease.

We talk about obesity when the excess of body weight are at least 30%.

To have a correct estimate on quality and quantity of the fat distribution some measurements are necessary:

• BMI fixing to 30 the limit beyond which we talk about obesity

• the waist-hip ratio, whereby one is obese if this ratio exceeds the value of 0.85 in women and 0.95 in humans

Many of genetic studies have hypothesized an individual tendency to obesity. It seems that about 70% to variability of body weight is attributable to genetic factors, but these do not justify by themself the increase of obesity. In effect in latest 20 years the genetic pool has not undergone significant changes, while the incidence of obesity has had an increase over 30%. Certainly the process has not a unique cause but several factors that take place : genetic, physiological, familial, psychological, social and behavioral.

Have been identified as many as 41 chromosomal disorders wich including the obesity in their phenotypes.

The more frequent are:

• Ulnar-mammary syndrome Schinzel syndrome or (UMS)

• Thyroid hormone resistance syndrome (THRS)

• Familial partial lipodystrophy Dunnigan (FPLD)

• Prader-Willi syndrome (PWS)

• Posterior polymorphous corneal dystrophy (PPCD)

• Insulin resistance syndromes (IRS)

• Angelman syndrome with obesity (AGS)

• Albright hereditary osteodystrophy 2 (AHO2)

• Achondroplasia Syndrome (ACH)

Recently it was found furthermore a protein ( SH2B1 ) that influence on sugars absorption and on the functioning of leptin and insulin. The people in wich this protein is inhibited are obese, while in those that it is increased are very thin and not gain weight even with a hypercaloric diet.

According to another study the predisposition to obesity it depends on the abundant presence of a certain types of bacteria in the stomach or in the intestines, the same wich generate some inflammation disorder such as colitis and Chron's disease.

Some researchers have found that obesity can be caused by a wrong comunication between neurons. The sense of hunger and satiety is regulated in hypotalamic nucleus and depends to many signals from the whole of body and mediated to some neurotrasmitters ( such as serotonin, dopamine, norepinephrine ). It is an extremely complex process that can go easly shorted .

Furthermore ,it is well know that our body has a system for managing stocks of energy based on the activity of two antagonist hormones: glucagon and insulin. The system is projected to manage the food shortage, therefore it tende to accumulate as much as possible when there is plenty of food and and waste as little as possible when there is dearth of food.

The hormonal problems contributing for a share of less than 5% in the onset of obesity. Their recogniton is of paramount importante for an adequate therapeutical approach. The main endocrinological diseases contributing of obesity are:

• Cusching's syndrome

• hypothyroidism

• Growth hormone deficienty

Parental influence on nutritional behaviour in an overweight or obese child are produced through two ways: the first is the "modeling", a process of social learning based on observation of behaviours of significant people for the person who observe.The child who observes the parents eating behavior quantitatively and qualitatively wrong, tend to imitate it and consider it appropriate and appreciated.

The second way of parental behavior that may infuence the develop and the maintenence of obesity in children , is represented by the use of food by parents to satisfy emotional needs of children or to promote an appropriate behavior.

The psychologists agree that the obese subject have developed a food addiction, similar to other addictions, but more difficult to face because the subject can not completely abstain from substance ( he can not stop eating!) and there is not difficult to obtain food.

The psychological motivation although it may not be the origin of the disease, is almost always the cause of its chronicity.

Another psychological mechanism is the one that sees food as a refuge, as a substance that alleviates the suffering experienced during the day. In this case we speak of "emotional hunger".

During the course of the disease, the obese man loses self-esteem because of failure to weight loss: the physical and psychological situation worsens progressively, triggering a mechanism by which it is very difficult to escape.

To all these factors obviously it adds a more sedentary life and a consumption of junk food (fatty foods cheap, industrially prepared foods), high in fat and sugar.

To influence our behavior, there are many social factors that have had and have negative consequences on the way of eating and physical activity levels, namely the modernization and globalization,the urbanization (through other factors such as transport, communication, food availability, health services and employment changes),the socio-economic status, the attitudes toward health and fitness, the body image (in towards greater emphasis on thinness), the government and local authorities (who contribute with their actions to reduced activity and increased intake of high calorie foods), the fast-food restaurants (which are now rampant and offer foods with a large content in fats), the marketing, the advertising , the media and the consumers (which influence the demand for food for the obesity development).

This Hub does not presume to explain the many and complex causes of obesity. Simply is the result of my research and of some my personal considerations.

Being aware of the reasons that lead us to be obese is important to understand which of these factors can be modified and those can not, which factors instead we must to know deeply to face them better in order to have a realistic view of our problem, essential thing for our success.