1) INTRODUCTION: Obesity is a global problem and its the prevalence is constantly rising. Overweight and obesity are key risk factors for many diseases. Obese patients are a greater economic burden for the state, they often rely on the help of others. The goal of obesity treatment is to reduce weight and then keep it within the recommended range. In an obese patient, it is not always just about the actual weight loss, but also about treating the associated diseases caused by obesity. Bariatric surgery allows patients to lose weight in a relatively short period of time and has a very positive effect on associated diseases. 2) OBJECTIVE: The aim of this diploma thesis was to evaluate the physical and mental condition before and after gastric bypass and to determine whether this surgery has a positive or negative effect on the physical and mental condition of the patient. The objective was further divided into sub-goals and hypotheses. 3) METHODOLOGY: The research was carried out using a quantitative method. This is an observational study, in which the mental and physical condition and advancement of patients who were about to undergo bariatric surgery - gastric bypass - were monitored for 6 months. Mental status was monitored using four standardized questionnaires: MAF, HADS, iADL, SF-36 in four time...

INTRODUCTION TO THE ISSUE: Obesity together with possible occurrence of many difficulties carries with it negative effect on physical and mental health. Many patients with severe obesity (class 3) cannot do physical activities or usual daily activities. These patients suffer from feelings of inferiority, decreased self-esteem and other mental issues. It could be classified as a vicious cycle for patients, but the bariatric surgery offers a way out. A gastric bypass is one of the bariatric procedures which is very helpful to reduce the weight of the patients who belongs into class 3 obesity. OBJECTIVES, METHODOLOGY: The main goal of this study was to find out if applying the gastric bypass to patients has positive or negative effect for their obesity level, quality of life, physical and mental state. The research sample was consisted of patients who were about to undergo gastric bypass. The patient's weight, BMI and body fat ratio were monitored to obtain data related to the assessment of the severity of obesity. The quality of life was evaluated using the SF-36 questionnaire (Short form 36). The standardized MAF (Multidimensional Assessment of Fatigue Scale) was used to review of patient's fatigue. The mental state of patients was subjectively assessed using the standardized HADS scale (Hospital...