Is obesity written in genes?

Obesity is one of the chronic and civilization diseases. The latest data from the World Health Organization report (WHO) indicate that as many as 59% of adults are struggling in European countries with obesity or overweight. This problem also affects 1 in 3 school age children. Due to such a large scale, it is worth knowing the causes and threats associated with this disease and answer the question: Is obesity written in genes?

Abstract

• Obesity is conditioned, among others, by genetic, environmental, psychological and hormonal factors of the body. The dominant role in the development of this disease is attributed to individual behavior and habits that make up the contemporary lifestyle of a given individual.
• The genetic conditions of obesity are very complex. It is estimated that there are about 600 genes that are involved in weight regulation processes.
• The most important consequences of obesity are health problems (high risk of many serious diseases) and psychological (e.g. reduced self -esteem, a sense of rejection, lack of self -acceptance).

Obesity - definition

The World Health Organization defines obesity as Incorrect and/or excessive fat growth. Another definition says that obesity is an increase in body weight (well above normal values) conditioned by excessive fat development. The principles of correct weight classification are based on anthropometric indicators that provide information on individual body parameters. BMI body mass indicator is considered to be the most useful (though not the only) diagnostic method of obesity (body mass index). He does not convey a direct measure of obesity (does not take into account the body composition, including muscle and bone masses), but it is considered the most practical because it does not require specialized equipment and is non -invasive. BMI is calculated by dividing body weight through an increase to a square (kg/m2). According to WHO standards, obesity is recognized in adults at BMI value ≥ 30 kg/m2. This result is independent of age and sex. The second indicator, used in practice for the diagnosis of obesity, is WHR (Waist -Ship Ratio). This is the ratio of the waist circumference to the hip circuit. This meter indicates the so -called Central obesity, i.e. excessive accumulation of fat in the abdominal region. To calculate the WHR indicator, you should measure the narrowest place in the waist and the widest in the hips, and then divide the waist circumference through the hip circuit. In the case of this indicator, the norms for men and women are different:

• WHR> 0.8 - indicates abdominal obesity in women;
• WHR> 1.0 - indicates abdominal obesity in men.

In specialist and scientific studies, more precise methods are used to determine the fat content in the body, including Nuclear magnetic resonance imaging, computed tomography or measurement of electrical conductivity of the system.

Is obesity saved in the genes?

The genetic conditions of obesity are very complex. It is estimated that there are about 600 genes that are involved in weight regulation processes. It is also worth noting that this disease is hereditary. Obesity in both parents increases the risk of this disease in adults as many as 13 times, but if it concerns one parent-4-5 times. The inheritance of the tendency to obesity is as much as 33%. Research results They do not indicate one gene that is directly responsible for obesity. A single mutation is very rare for the disease - the interaction of many genes is much more often needed. Genes related to:

• energy balance control, e.g. leptin coding gene, vulnerabilities gene (FTO);
• appetite control, e.g. leptin coding genes (LEP) and neuromedine B (NMB);
• process of adipogenesis, e.g. a gene encoding insulin -dependent protein (INSIG2);
• lipid metabolism, e.g. genes encoding aquaporine (AQP7) and peripine (plin);
• oxidation of fatty acids, e.g. a gene encoding syrtina 1 (sirt1);
• insulin secretion, e.g. insulin coding genes (INS) and interleukin 1 (IL-1);
• and support genes, e.g. catalase (Cat) and resistin genes (retn) genes.

The results of numerous studies indicate The significant importance of the leptin gene (Gen Lep) and its receptor (LEPR gene) in the formation of obesity. It is a peptide hormone, and its gene is on chromosome 7. Leptin is produced primarily by fat. It inhibits the signal trails related to the feeling of hunger, and stimulates the routes responsible for feeling satiety in the hypothalamus. Thanks to this, it provides information about the body's energy reserves to the brain. To sum up: Leptin regulates our appetite and makes us feel satiety at the right time. The more fat in the human body, the greater the level of leptin in the body. But The excess of this hormone means that the cells cease to be sensitive to it and leptin signal does not reach the brain. Consequently, despite eating a large portion of a meal, we do not feel satiety. This phenomenon is called "leptin resistance". This problem is important because it leads to the mechanism of a vicious circle - for a large amount of food leads to the accumulation of excessive amounts of fat, which in turn causes an increase in leptin, which in this concentration does not perform the function of braking appetite. Another important gene, very strongly associated with obesity, is a gene of vulnerabilities to obesity (FTO), located on chromosome 16. Most likely The unfavorable variant of the FTO gene is related to the type of nutritional preferences and the control of food intake. Studies indicate that the mentioned gene is active in the hypothalamus and can affect the feeling of hunger and hormones related to appetite. People with an unfavorable FTO variant feel satiety slower (which leads to eating more food), have greater tendencies to overeating and more often consume products of inferior quality. The influence of the gene can be observed during childhood, and having one of its adverse variants increases the risk of obesity, overweight and other diet -dependent diseases (e.g. type II diabetes, liver fatty, cardiovascular disease). Research also indicates that people with The negative variant of the FTO gene have a higher BMI indicator (on average by 1.1 kg/m2), larger body weight (on average 3 kg) and a larger waist circumference (about 2.3 cm). On the example of the genes described above, we can see that in the development of obesity genetic predispositions are important. However, not every person with an adverse variant of genes that increase the risk of obesity is doomed to her. Very often prevention - a proper diet and active lifestyle - allow you to minimize the risk of this disease and its negative effects. This is confirmed by the fact that the impact of the adverse variant of the FTO gene on body weight is 30% lower in people who are physically active than those who lead a sedentary lifestyle.

Other causes of obesity

The pathogenesis of obesity is multifactorial. Its occurrence is influenced not only by genetic factors, but also environmental, psychological or endocrine disorders. A very important environmental factor, significantly increasing the risk of obesity, is Limiting physical activity and a sedentary lifestyle. This is related to the development of transport and mechanization of work at the same time increased access to food (including for fast food products that are caloric and not very nourishing, but easily accessible and cheaper than their healthy substitutes). It is also worth emphasizing that once food was mainly used to satisfy the hunger and nutritional needs of the body, while now its role also became pleasure. The result is that in modern times we often eat more than we really need. The psychological conditions of obesity include, among others Disorders of the self -regulation mechanism, beliefs and expectations of the individual and difficulties in dealing with stress and emotions. Self -regulation disorders consist in the inability to control the amount of food consumed and lead to overeating. Negative self -image, low self -esteem, pessimism and external location of a sense of control are beliefs and expectations that can also lead to excessive food consumption. Stress and difficulty dealing with emotions make food become a form of dealing with problems. It distracts attention from unpleasant stimuli, is a way to avoid a threat, limits unpleasant emotions, and calming. Endocrine disorders may also cause obesity. The most common is advanced, Untreated hypothyroidism, Cushing syndrome or growth hormone deficiency. Although obesity is conditioned by many factors, it The dominant role is attributed to individual behavior and habits that make up the lifestyle of a given individual. It should be remembered that the basis for the development of excessive body weight is the disturbed energy balance (the situation in which the energy consumed exceeds the spent energy).

Health and social consequences of obesity

Obesity affects Negatively on various aspects of life - primarily for our health. People with excessive body fat have a greater risk of serious diseases, including: type II diabetes, cancer, joint degeneration, respiratory, digestive and cardiovascular diseases (especially hypertension, ischemic disease and heart failure). People with obesity are also exposed to Negative social and psychological consequences. They often meet with rejection, they are seen as less attractive. Excessive body weight often adversely affects self -esteem, it causes a lack of faith in your own abilities. In addition, it may result in the appearance of negative emotions (sadness, regret and a sense of loneliness). All this means that the risk of depression increases in obese people (especially in teenagers). These people often have reduced social, cultural and physical activity. They areolate themselves for fear of rejection and because of a lack of trust. The result may be difficulties in social and family relationships. Obesity is a serious health and social problem. It contributes to the development of many serious diseases, therefore - although sometimes genetic conditions do not favor - it should be fought. The issue of obesity is very complex. In the above article, only some aspects of this disease have been discussed. The development of technology and research has meant that we know more and more about obesity, its negative health effects and treatment methods, but there is still a need to deepen knowledge regarding this issue.

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