Obesity is genes, bad habits or predispositions?

Why is obesity a disease?

For years, adipose tissue has been considered merely as the body’s energy store. However, a number of studies have shown that it secretes a number of substances that affect the functioning of organs and tissues. Currently, adipose tissue is said to be another endocrine organ due to the fact that it secretes a range of proteins that exhibit actions mainly attributed to hormones. A certain amount of adipose tissue is necessary for, for example, puberty and fertility preservation, but an excess of it in the body causes a pathological condition. Particularly dangerous are fat cells located in the abdomen (what we mean here is the visceral fat tissue located around the organs).

Adipose tissue plays a huge role in metabolic processes:

•  It secretes many substances that not only affect the regulation of hunger and satiety (leptin, visfatin, resistin), but also increase inflammation (interleukin-6).
• It affects the metabolism of steroid hormones (aromatase, dehydrogenase).
• Fat cells have many receptors for, among others, insulin, glucagon, TSH or angiotensin, which can impede their proper function in the desired areas of the body.

Although all these names sound complicated, they show what a complex “organ” with multidirectional effects adipose tissue is. Its excess leads to insulin resistance, impaired glucose tolerance, and ultimately type 2 diabetes.

In addition, it influences the development of hypertension, cholesterol disorders, chronic inflammation in the body, and increased risk of blood clots. Unfortunately, each of these disorders entails further complications and contributes to the development of the metabolic syndrome. Advanced obesity usually requires pharmacotherapy to break the circle of mutually driving disorders.

Genetic determinants of obesity

To date, the gene directly responsible for obesity has not been found. Mutations of single genes, as well as entire sets of genes, can have an impact, which can translate into disorders of component metabolism, absorption or appetite.

Obesity can also be a component of rare genetic disorders. Their pathogenesis is not fully understood, but often results from damage to more than one gene. In addition to pathological obesity, caused by, among others, hyperphagia and a lowered basal metabolism of almost 15 percent, they are also accompanied by other developmental defects (intellectual disability, organ disorders).

• Polygenic obesity

The most common obesity is that which is polygenically determined. This type of obesity is the result of interactions between genes and the environment. It does not involve a specific mutation or aberration of the chromosomes as those described above, but polymorphisms that alter protein function. Indeed, susceptibility to the occurrence of obesity is determined by genes, but it is the quantitative and qualitative composition of the diet and physical activity that influences whether or not excess body weight will occur. Depending on the genotype, there is an increased tendency towards obesity to varying degrees. However, the correlation of obesity with physical inactivity is highlighted here. Introducing regular exercise and controlling the proportion of fat in the diet will be the best way to combat weight gain and protect against the risk of obesity.

• Genetic testing

An increasing number of dietetic clinics are offering genetic testing to personalise dietary recommendations. Awareness of carrying specific gene polymorphisms that increase the risk of metabolic disorders can be used when introducing interventions. It is important to bear in mind that such a test does not take all genes into account, and instead focuses on a select group which may carry some risk.

Impact of intestinal microflora on obesity

The microbiota inhabiting the human body is characterised by great diversity. Depending on the section of the gastrointestinal tract, there are different, characteristic species of microflora. Differentiation is necessary because these bacteria have different metabolic activities that affect human physiology. They facilitate the breakdown of undigested parts of the fibre, can produce essential vitamins or regulate host immunity. In abnormal quantities, the bacteria increase the amount of kilocalories absorbed, facilitate fat accumulation and affect appetite. The desired microflora, in turn, supports the correct metabolic processes and regulates the intake of the right amount of kilocalories with meals.

So how do you take care of the correct gut microflora? It should be properly nourished with products rich in dietary fibre. It is worth enriching the daily diet with oats, barley, peas, beans, apples, citrus or Psyllium plantain and inulin. Including 10 g of inulin in the daily diet contributes to weight loss and fat loss compared to the placebo group, according to scientific studies.

Another group of substances that influence normal composition of intestinal microflora are polyphenols. They are found in plant products and are mainly known for their antioxidant and anti-inflammatory effects. Together with the gut microbiota, they form a mutually dependent duo. Berries, cocoa, green and black tea, legumes, pomegranate, flaxseed and cereal products are the most abundant in these ingredients.

The mechanisms and interrelationships described show how complex the human body is and the impact a balanced diet has on every level. When we have a healthy and varied diet, we simultaneously support the gut microflora, which influences the feeling of satiety, regulates glucose and reduces the desire for snacking, making it easier to make healthy food choices.

Diseases that contribute to obesity

In addition to the genetic determinants of obesity, there are diseases that, directly or indirectly, can make it difficult to maintain a normal body weight. Secondary obesity occurs in certain endocrine diseases, genetic diseases or diseases of the hypothalamus and pituitary gland. Weight problems are seen in people struggling with hypothyroidism, which can result from pituitary damage, Hashimoto’s disease or removal of the thyroid gland.

Another group of diseases are those related to the hypothalamus (an area in the brain), which is responsible for the secretion of hormones, the circadian rhythm or the feeling of hunger and satiety. Disorders in this area can be associated with excessive appetite and lack of satiety. Examples of such diseases include Prader-Willi or Bardet-Biedl syndrome. The problem of hyperphagia can occur with radiotherapy-induced hypothalamic damage or during surgical intervention.

It is not only diseases, but also the pharmacotherapy used, that can influence the problem with feelings of satiety or increased appetite. Medicines that increase the risk of excessive fat accumulation include neuroleptics, antidepressants and antiepileptics, tranquillisers, steroid hormones, beta-adrenergic drugs, as well as antidiabetic drugs – insulin and some sulphonylurea derivatives. This does not mean that the listed medications should be discontinued, as they are prescribed as a primary treatment for certain diseases. Using the pharmacotherapy indicated above, more attention should be paid to exercise and nutritional choices made.

The environment and obesity

Simple obesity, i.e. resulting from a positive energy balance, is most common among children, adolescents and adults. There is a perception that if the mother is obese, the child is bound to be too! Although the probability is high (80 percent if the parents were obese, and 40 percent when only one parent was obese), obesity is not mainly due to genes, but to the transmitted dietary and lifestyle patterns.

Of course, there is a hypothesis for the innate determinant of obesity – the thrifty genotype theory, resulting from the body’s adaptation to store energy for times when access to food will be limited. Such metabolism was essential in prehistoric times, when game had to be hunted or wild fruits and plant shoots had to be picked, and a meal came along once every few days/weeks. Nevertheless, it is currently difficult to determine how many primary genes are active in our genotypes and this information can be treated more as a curiosity.

The focus should be on what we have a real influence on. Even the first days in the womb are important for the metabolic health of the baby. As research shows, excessive weight of the mother, as well as poor nutrition during pregnancy, promotes the development of obesity in the child, the development of insulin resistance or hypertension. Both too high and too low an infant’s birth weight carry a high metabolic risk. Importantly, it is not only the amount, but also the type of food consumed by the pregnant woman that influences the child’s later taste preferences. The flavours of the products penetrate the foetal waters, the baby gets used to them and remembers them as pleasant and safe memories.

Then, during childhood, they are more likely to have them. As you can see, the formation of eating habits starts from the first days of life. They replicate the eating habits they observe among their loved ones. At this stage, it is important not to teach emotion regulation with food.

In addition to the provision of excessive calories, physical activity has a huge impact in the development of obesity. There are many solutions such as lifts, escalators, electric scooters that reduce our energy expenditure.

Summary

Whatever the cause of the resulting obesity, the condition of excessive body fat is devastating to our bodies. The treatment process should be undertaken as soon as possible before the changes are irreversible. The treatment of obesity requires an interdisciplinary approach and multidirectional action. Many times the support of a psychologist or psychiatrist will be necessary in addition to pharmacotherapy and a balanced diet. If you are struggling with excess weight and heading towards obesity, try to stop the process as soon as possible. The most effective method of obesity prevention is a diet based on correct nutritional principles combined with regular exercise. If a slimming diet is proving ineffective, the first step should be to review the calories, pay attention to snacking, drinks consumed and look at physical activity. Afterwards, it is a good idea to carry out basic tests and nourish the intestinal microflora. Only at the very end can the cause be sought in the genes, as the mutations described above are quite rare.

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