Obesity is a disease that affects not only the elderly or the sick but also children. Interestingly, it has been noted that newborn babies are increasingly being born with a higher birth weight. Research shows that the prevalence of obesity is increasing rapidly worldwide and is influenced by genetics. The treatment and diagnosis of obesity requires a lot of effort and, importantly, is the cause of numerous complexes, health problems and complete social withdrawal of the patient. When do we talk about obesity? What influence do genetics have on obesity? When to go to a specialist?