A túlsúly, az elhízás és a táplálkozás kapcsolata [The Relationship between Overweight, Obesity, and Nutrition]
In our age, in the more developed part of our world, food is available to people with virtually unlimited access, as a result of which obesity has become a global problem, an epidemic that is increasingly threatening humanity. Obesity is significantly influenced not only by human genetics but also by eating habits, dietary composition, energy intake, which provides an opportunity to develop strategies to control body weight and obese people to achieve significant weight loss. We can talk about a global problem, as there are currently 1.5 billion people with overweight or obesity, and this number is constantly growing. In different countries in Europe, 15-18% of adult men and 18-20% of women are obese, and in some countries another 40% of men and 30% of women have overweight. The proportion of overweight and obese people ranges from 10 to 20% in northern Europe and from 20 to 40% in southern Europe. In developed industrial countries, coronary heart disease and cancer are the leading causes of death, closely linked to lifestyle and obesity.
The incidence of these diseases can only be reduced if people change their eating and fitness habits in parallel with quitting smoking, as changing the diet and putting regular exercise on the agenda can bring the greatest success to both in the prevention of diseases and in the treatment of diseases that have already developed. These facts inspired us to write the book. In doing so, we also faced problems such as we could not always use SIunit terms in cases where, e.g., we wanted to write mass instead of weight, but weight was not applicable in the context. Instead of calories, we tried to write joules in the content, or if one of the sources wrote about calorie intake, we replaced it with energy. The procedure was similar for vitamins, when the International Unit (IU) was converted to mg/kg or μg/ kg, for macro- and micro-nutrients, where ppb and ppm were rewritten in the same way for the units of measurement. This attempt caused a more significant problem in the case of weight and mass, the solution in the other cases being relatively simple. In the different chapters, we were sometimes forced to repeat content in order to make the problem more understandable. In almost every chapter, the role of energy balance, the relationship between energy intake and obesity, and the role of exercise in shaping a healthy lifestyle come to the fore. One can only gain weight from what we eat or drink. The only exception to this is water, which, as the final product of terminal oxidation, has no energy content. The macronutrients in our foods all have significant energy content, but how this energy can be utilized and what it can be used for depends on many factors.
To understand the mechanism of obesity, we describe the chemical composition of foods at the beginning of the book. In addition to carbohydrates, proteins, and fats, we discuss the role of minerals, vitamins, natural colours, flavours, and various food-forming organic compounds in nutrition. We deal briefly with the most important enzymes in food production, food additives, toxins produced by microorganisms and other substances, and only touch on the impact of packaging materials and cleaning and disinfecting agents on food quality briefly. In a short chapter, we deal with the role of functional foods in nutrition, their production, the bioactive components of milk, pro- and prebiotics. We discuss why meat and eggs out of our animal-originated meals and soybeans, certain types of grains, vegetables and fruits, and nutritional germs out of the plant-originated ones are functional foods. This chapter discusses selenium-fortified foods and the beneficial effects of red wine on the human body. After the basics of food science, the reader can get acquainted with the biochemical foundations of obesity, including energy formation and fat storage as well as biochemical reactions related to obesity. All the processes by which the body can produce fat from the absorbed nutrients are discussed in detail.
After the biochemical foundations, the molecular basis of obesity will be discussed, within which we will discuss hereditary disorders of obesity, Mendelian, recessive, and gene-deficient forms of obesity. We write about structural variations in the genome, polygenic forms of obesity, genetic studies, and genome-wide studies. The next chapter discusses the relationships between energy intake, eating behaviour, and obesity. Here we describe the factors influencing appetite, satiety, the role of access to food, food composition and nutrient density, the effects of palatability, variety, eating habits, frequency of eating and portion size on obesity. In addition, influencing factors, such as restrained eating behaviour, the effects of emotions and stress on eating, food dependence, lifelong energy balance control, and weight control mechanism, are also discussed. This is followed by a description of weight loss strategies, methods for maintaining weight retention, and obesity. We discuss the relationship between nutrition and exercise, analyse energy intake and expenditure, and discuss the relationship between weight loss and health maintenance. We describe the setting of weight loss goals, incentive control, problem solving, and methods developed to prevent relapse. We discuss the effects of home or supervised exercise, short intense or prolonged less strenuous exercises, the use of exercise equipment, and media on weight loss. In the following, we analyse the health risk of obesity. Within this, we discuss childhood obesity, the contribution of the environment to obesity, the diseases associated with obesity, the psychosomatic aspects of obesity, the links between death and obesity, and options for preventing obesity.
At the end of our book, in the Selected Chapters, we describe the biochemical foundations of low-carbohydrate, low-energy, and ketogenic diets, among others, and their implementation in practice. We focus on our experiments in the production of the high-nutritional functional foods, low-carb bread, in order to introduce the esteemed Reader to the scientific background behind our results. We hope that with our book we can draw attention to the fact that obesity is a public disease and that much more should be expended to sacrifice for pre-obesity education, treatment of obesity, and healing of sick people. These “sacrifices” would not only serve the interests of the individual but would also bring significant benefits to the national economy, as less costs would be needed to spend to heal sick people, and they would be able to do their beneficial work in everyday life for longer.