## 1 Introduction  
In the human population, obesity has become a pandemic of the modern era [1]. Numerous diseases and health complications are associated with obesity and excess body weight and are manifested in cardiovascular diseases, various types of cancer, hypertension, type 2 diabetes, polycystic ovary syndrome (PCOS), and many others [2, 3]. But less often considered is the social isolation and mental state [4] often accompanied with anxiety and depression [5], which [PERSON] [6] describes as follows: \"Imprisoned in every fat man, a thin man is wildly signaling to be let out\". Research shows that one of the important steps in \"releasing the thin man\" and solution to \"globesity\" [7] is the establishment of a balanced diet, adequate physical activity, and changing behavior and lifestyle [2, 3, 4, 5, 6, 7, 8]. Therefore, a number of strategies have been launched at the world level, in the design of appropriate educational programs and body weight regulation programs, because this implies an improvement in the general condition of the population [9; 10], with the aim to start at childhood because prevention is better than to cure [11]. The parameter used to classify moderately active people into groups of malnourished, normally nourished, obese, or overweight people is the body mass index (BMI) as a ratio of body mass to the square of body height (kg/m\({}^{2}\)). Values of the BMI for normal nourished individual is in the range of 18.5-25 kg/m\({}^{2}\), while the classification of \"overweighed\" starts with a BMI \(>\) 25 kg/m\({}^{2}\), and obesity with a BMI \(\geq\) 30 kg/m\({}^{2}\)[7]. [PERSON] et al. [12] investigated the changes in body height, body mass, and BMI in the period from 1999 to 2016, analyzing the data available in the sources as (i) the National Health and Nutrition Examination Survey (NHANES) [13], (ii) National Health Interview Survey (NHIS) [14], and (iii) Behavioral Risk Factor Surveillance System (BRFSS) [15]. The mean height of the female and male population remained the same (1.76 m for men and 1.62 m for women), while the body mass values have shown a proportional increase within the observed years (1999 to 2016), and thus BMI increased proportionally. Unfortunately, from the average BMI in the population in 1999 (men: 27.6 kg/m\({}^{2}\); women 28.1 kg/m\({}^{2}\)), the values for men and women increased to 29.1 kg/m\({}^{2}\) and 29.6 kg/m\({}^{2}\), respectively [12]. Individuals who decide to reduce their body mass, which will consequently result in a reduction in their BMI, often want to see some results hastily, otherwise they rapidly return to their old food patterns and/or behavior, wherefore the yo-yo effect occurs, meaning that the person then feels even worse [16]. Therefore, the perception of effective weight loss is especially necessary for people with a BMI \(\geq\) 30 kg/m\({}^{2}\) in order to remain stable after restrictive energy intake. Forehand recognition of the factors that influence an individual's increased body weight (eating habits) helps nutritionists and medical doctors design appropriate body weight regulation programs in which the ketogenic diet pattern is often used, which may modify lipid profile and the inflammatory state of the body [17] and can help with weight loss, visceral adiposity, and appetite control [18]. [PERSON] et al. [17] highlighted the presence of different ketogenic diets depending on the amount of carbohydrates, but the majority of them are characterized by the minimization of energy and carbohydrate intake [19]. In the standard ketogenic diet, there is a preferred share of carbohydrates under 5% in the daily energy intake, while the share of fats is dominant (\(\approx\)60%), and the remaining part is made up of proteins (35%) [20]. The limited intake of carbohydrates, with a dominant share of fats and a moderate intake of protein, results in the use of ketone bodies from fat metabolism.