Background: The World Health Organization (WHO) classifies malnutrition as the biggest threat to public health worldwide, and this condition is observed in 20–60% of hospitalized patients. Malnutrition is a state of the body in which due to insufficient supply or incorrect absorption of essential nutrients, the body composition changes and the body’s functions are impaired. Malnutrition is associated not only with reduced body mass index but also with obesity. Summary: Obesity is defined as a paradoxical state of malnutrition, which despite excessive energy consumption is associated with a shortage of individual microelements. Deficiency or lack of homeostasis of essential micronutrients can significantly affect daily performance, intellectual and emotional state, but also the physical state of the body. Food deficiency can also contribute to further weight gain or the development of other metabolic diseases. Micronutrient deficiency may include not only incorrect dietary choices and insufficient access to nutrient-rich foods but also changes in the absorption, distribution or excretion of nutrients, and altered micronutrient metabolism resulting from systemic inflammation caused by obesity. An effective therapy method recommended for people with morbid obesity is bariatric surgery aimed at both weight loss and improving quality of life. Unfortunately, the effects of these treatments are often medium- and long-term complications associated with micronutrient deficiency as a result of reduced consumption or absorption. Therefore, the use of bariatric surgery in patients with extreme obesity can affect the metabolism of microelements and increase the risk of nutritional deficiencies. Key Messages: Studies by many authors indicate a higher incidence of food deficiency among people with excessive body weight, than in people with normal body weight of the same age and same sex. Monitoring the concentration of minerals and vitamins in blood serum is a good practice in the treatment of obesity. The proper nutritional status of the body affects not only the state of health but also the effectiveness of therapy. The aim of the review was to present the issue of malnutrition in the context of obesity.

The problem of overweight and obesity among children and adolescents has now become a major public health challenge worldwide. The aim of this study was to assess the effect of age and gender on body composition components and anthropometric indices of children and adolescents aged 6–15 years; in addition, the study aimed to assess body composition indices in relation to BMI (Body Mass Index) levels. The study was conducted at the end of 2019 and in the first quarter of 2020 among 181 pupils attending primary schools. Waist circumference, hip circumference, body weight, and body height were measured. The collected data were used to calculate and then to analyse BMI, WHR (Waist-Hip Ratio), and WHtR (Waist to Height Ratio) indices. Body composition was determined with the use of the Bioelectrical Impedance Analysis (BIA). The analyses’ statistics were performed using IBM SPSS Statistics 24 and Excel. The statistical methods used included Chi² tests of independence, one-factor analysis of variance, and two-factor analysis of variance taking into account the level of α = 0.05. Based on the results, there were no statistically significant differences in the gender and age distributions of the BMI groups. However, the analysis of interaction effects confirmed that there were statistically significant differences according to pubertal age and gender in body fat, muscle mass, hydration, and WHR. Body composition in boys and girls before the age of 12 is similar while, after the age of 12, there are differences between boys and girls in terms of body composition so there is a need to deepen the assessment of body mass, especially in adolescents at the age of puberty, by body composition analysis using the BIA method.

Introduction: The results of recent decades of research show an increase in the incidence of mental disorders, such as depression. The World Health Organization estimates that the disorder affects approximately 264 million people worldwide, and will become the most common health...