With the course of the history of mankind, there have been extraordinary changes in the perception of obesity. In the Middle Ages, for example, it was considered a graphic expression of a high social status. A full woman was a model of health and sexuality, and obesity in this case rarely led to aesthetic problems. At present, however, because of the health hazard, obesity is defined as one of the most serious metabolic disorders. Obesity as a problem of modern society is the topic of conversation for today.
What is obesity?
Obesity can be defined as weight gain, expressed in abnormal deposits of triglycerides in fatty tissues with pronounced negative effects on the body. That is, not every fullness is obesity. Since accurate measurement of body fat amounts to expensive and inaccessible studies, a common method for determining obesity, the so-called "body mass index", has been adopted in the field of health. The relationship between the weight of a person in kilograms and the height in meters in a square described in the distant 1896 A. Quetelet and gave rise to the creation of a general scheme for calculating the mass index:
Low body weight - less than 18.5 kg / m 2
Optimum weight - 18,5 - 24,9 kg / m 2
Overweight - 25 - 29.9 kg / m 2
Obesity 1 degree - 30 - 34.9 kg / m 2
Obesity 2 degree - 35 - 39.9 kg / m 2
Obesity 3 degree - more than 40 kg / m 2
In 1997, the World Health Organization (WHO) adopted a weight classification standard in accordance with this scheme. But then scientists noted that this indicator does not give any information on the amount of fat, and more importantly, where it is located in the body. Namely, this is a fundamental factor in the development of obesity. Regional distribution of adipose tissue is an important aspect of identifying the extent of obesity, setting the frequency and severity of the manifestations of concomitant diseases. The accumulation of fat in the abdominal region, known as the Android (central, masculine) is associated with a significant increase in the health risk, much greater than in the female type of obesity. Thus, the definition of the body mass index is most often accompanied by measuring the waist volume. It was found that the body mass index ≥ 25 kg / m 2 in combination with the waist circumference ≥ 102 cm in men and ≥88 cm in women significantly increases the likelihood of complications. Among them: arterial hypertension, dyslipidemia (impaired lipid metabolism), atherosclerosis, insulin resistance, type 2 diabetes, cerebral stroke and myocardial infarction.
Statistics of obesity in the world
The number of obesity cases is growing all over the world at a rapid pace, reaching epidemiological proportions. Obesity problem of modern society has become quite quickly - over the past couple of decades. According to official statistics, currently 250 million people on the planet are diagnosed with obesity and 1.1 billion are overweight. This trend will lead to the fact that by 2015, these indicators will grow to 700 million and 2.3 billion people, respectively. Most worrying is the increase in the number of obese children under the age of 5 - it is more than 5 million worldwide. Also of concern is the prevalence of type 3 obesity (≥ 40 kg / m 2 ) - it has increased almost 6-fold over the past decade.
Across Europe, obesity affects about 50% and overweight - about 20% of the population, with Central and Eastern Europe - the most affected areas. In Russia, the situation is extremely serious - about 63% of men and 46% of women in economically active age are affected by overweight, while 17% and 19%, respectively, are obese. The country with the highest level of obesity in the world - Nauru (Oceania) - 85% of men and 93% of women.
What leads to the development of obesity
Obesity is a violation of chronic metabolism, as a result of the complex interaction of endogenous (genetic characteristics, hormonal balance) factors and external conditions. The main reason for its development is considered to maintain a positive energy balance due to increased energy consumption, reduced energy consumption or a combination of both factors. Since the main source of energy for humans are nutrients, energy consumption is primarily associated with physical activity. Without the implementation of sufficient activity, energy is consumed weakly, the substances are not absorbed correctly, which ultimately leads to weight gain, obesity and the development of concomitant diseases.
Nutrition in the etiology of obesity
If several decades ago there were doubts about the importance of nutrition in the etiology of obesity, today, in modern society, it is proved that the diet is of paramount importance here. Food monitoring shows that over the last 30-40 years, energy consumption per capita has increased, and this problem will continue in the future. In addition, quantitative changes are accompanied by qualitative changes in nutrition. Consumption of fats in recent years has risen sharply, as useful mono-and polyunsaturated fatty acids "gave way" to saturated fatty acids. At the same time, there is a jump in the consumption of simple sugars, and consumption of complex carbohydrates and fiber has decreased. Foods high in fat and simple carbohydrates are preferred for eating because of their good taste. Nevertheless, they have a severe pronounced effect and an increase in energy density (calories per unit weight) - factors that easily lead to a positive balance of energy and subsequent obesity.
Importance of physical activity
Continued economic growth, the violent pace of industrialization and urbanization can minimize the need for activities that require physical effort. Our ancestors did not have to pay for physical work and getting loads. They were forced to do this by life itself. We, who live in cities, need to pay a considerable sum to visit a modern fitness center or swimming pool, exercise or go through a medical treatment session. Meanwhile, the movement is important for maintaining the normal structure and function of almost all organs and systems in our body. Its absence without valid reasons will sooner or later lead to pathological changes in the organs and tissues of the body, to general health problems and early aging.
Numerous epidemiological studies have shown that sedentary lifestyle is most often associated with an increase in the number of metabolic disorders, in particular, overweight and obesity. Interestingly, the fact that the ratio of reducing physical activity obesity is bi-directional, i.e., lack of physical activity leads to weight gain, and it is more difficult for people with overweight to initiate physical activity. Thus, the accumulation of excess weight deteriorates and leads to the formation of a peculiar vicious circle. It is the increased energy intake and decreased physical activity that is the cause of the observed jump in the prevalence of obesity at the present time. It is believed that nutrition has a greater share of risk, because through it we can more easily generate a positive balance of energy than compensate it later through physical activity.
Genetic obesity and heredity
Although obesity clearly carries a hereditary component, the exact mechanisms underlying it are not yet well understood. Genetic "codes" of human obesity are difficult to isolate, because a very large number of genotypes disintegrate under the influence of external factors. Science knows cases where whole ethnic groups and even families that are much more prone to obesity have been genetically determined, but it is still difficult to say that this is 100% hereditary, since members of these groups ate the same food and had similar motor skills.
Studies conducted among large groups of people with significant differences in the body mass index and the amount of fat, as well as among twins, show that 40% to 70% of individual differences are genetically predetermined. In addition, genetic factors affect mainly energy consumption and absorption of nutrients. At present, despite scientific and technical progress, it is difficult to say with certainty whether this is a genetic phenomenon - obesity.
The importance of some hormones in the development of obesity
In 1994, it was found that fat is a kind of endocrine organ. The release of the leptin hormone (from the Greek Leptos - low) gives hope for the discovery of a drug to combat obesity. Many scientists have begun searching for similar peptides in nature to artificially supply them to the human body.
- Leptin is a hormone of adipose tissue, which at the vascular level is proportional to its amount. Leptin acts on specific receptors located in the hypothalamus, which send satiety signals to the brain. He lets know when the body has received a sufficient amount of substances from food. Sometimes mutations of the gene responsible for the production of leptin occur. Individuals suffering from this mutation have a low leptin vascular level and they constantly feel the need for absorption of food. People constantly feel hunger and, trying to get full, they themselves provoke the development of pathological obesity. Supplying leptin from outside for these people is an extremely important point. However, however, often in obese patients, there are higher levels of serum leptin, but at the same time, appetite greatly increases. In such cases, resistance and substitutive leptin therapy do not have an effect.
- Grelinate is a hormone of the gastrointestinal tract, whose action is similar to that of leptin. It is defined as the hormone of hunger. His level rises before eating and decreases immediately after eating. Grelinate is used to develop a vaccine against obesity that will not allow it to reach receptors in the central nervous system and induce hunger. Often with obesity, this feeling turns out to be false, so it would be better to stop accessing the hunger hormone to the brain at all. This is a chance for a patient with obesity to begin to lead a normal life.
- Peptide YY is another hormone that participates in appetite formation. Produced in different parts of the small and large intestine after ingestion, this hormone slows down the emptying of the stomach, thereby improving digestion and absorption of nutrients and increases the feeling of satiety. People suffering from obesity have lower levels of YY peptide. It was found that the consumption of foods and drinks rich in protein, increases the secretion of peptide YY and prolongs the feeling of satiety.
- Adiponectin is another hormone produced in adipose tissue, which has a potential effect on the development of obesity. Although its role in the body has not been fully explored, it is clearly demonstrated that patients suffer from obesity, having a low level of adiponectin and vice versa - after a decrease in body weight, its concentration increases. Experiments performed on laboratory mice proved rapid weight loss after external application of adiponectin. Before the trials on humans, however, many questions should be answered.
Why is obesity such a significant disease?
The social significance of obesity is determined not only by the menacing dimensions, that it has reached among the world's population, but also the health risks it presents. Of course, the relationship between overweight, obesity and premature mortality has been proven. Moreover, obesity is one of the main etiological factors in the pathogenesis of a large number of diseases affecting the number of economically active population of the planet and leading to disability and disability. According to official data, about 7% of the total expenditure on health in some developed countries are given to treat the effects of obesity. In fact, this figure can be several times higher, since most of the indirectly related obesity diseases are most likely not included in the calculation. Here are some of the most common diseases caused by obesity, as well as the degree of risk that it poses to their development:
The most common diseases caused by obesity:
Significantly increased risk | Moderate risk | Slightly increased risk |
Hypertension | Cardiovascular diseases | Cancer |
Dyslipidaemia | Osteoarthritis | Back pain |
Insulin resistance | Gout | Developmental flaws |
Diabetes mellitus type 2 Sleep apnea Cholelithiasis | Asthma |
Obesity is a chronic metabolic disorder with very serious health consequences. Although to some extent its development is genetically predetermined, behavioral factors, in particular, nutrition and physical activity, play a decisive role in the etiology. So the appearance of excess weight or even obesity - all this will depend primarily on ourselves, and everything else is just an excuse.