Plant-based Diets and Body Weight and Selected Metabolic Parameters Management in Obese Patients.

Inclusion Criteria: * Age \>18 years (adults able to give informed consent to participate in the study) ≤ 60 years of age * BMI \>30 kg/m2 or BMI 25-29.9 kg/m2 with waist circumference in women 88 cm, in men 94cm. Exclusion Criteria: * age \<18 years and \>60 years, * severe medical conditions, including alcoholism, major and extensive surgery, chronic kidney and liver disease, history of myocardial infarction, unstable angina pectoris within the last 6 months, history of stroke within the last 6 months, cancer within the last 5 years, * psychiatric condition preventing participation in the study and cooperation with the investigators, * use of enteral or parenteral nutrition, * use of medications that cause significant weight loss (e.g., GLP-1 analogues) * pregnancy or breast feeding, * attempts to change dietary habits, including reduction of caloric intake and elimination of meat and animal products in the past 6 months, * lack of consent to participate in the study.