Taking into account the importance of correction of metabolic parameters in PCOS, diet therapy is offered. Diet therapy is appropriate as the first stage of treatment in patients with PCOS and IR, but the optimal diet has not been determined at the moment [8]. Purpose: to conduct an analysis of studies on the effectiveness of various types of diet therapy. Materials and methods. 12 articles from 2020 to 2022 were analyzed. Research results and their discussion. A review and analysis of a cohort study on the effects of a ketogenic diet (KD), in which 14 overweight women with a diagnosis of PCOS participated [1].The main argument for the use of KD in PCOS and IR is physiological ketosis [4], which occurs as a result of a low carbohydrate content in the diet, which in turn reduces the level of circulating insulin, and therefore the receptor for insulin-like growth factor type 1. As a result, production of androgens in both ovaries and adrenal glands is inhibited.The results of a 12-week study suggest that a ketogenic diet is appropriate for correcting metabolic disorders and obesity in PCOS and IR.The Mediterranean diet (MED) has proven to be one of the most effective diets in the treatment of metabolic and reproductive problems in women with PCOS and IR [5].The results of the research showed that both approaches to diet therapy are productive in normalizing metabolic processes. It is worth noting that the group of patients who used the MED/LC diet combination showed excellent results in the normalization of the menstrual cycle (86.7% recovered a regular menstrual cycle).Соnclusions.  The advantages of KD are a good result in reducing weight and anthropometric indicators in a short period of time. The most promising in the context of PCOS and IR treatment with further introduction into the patients' lifestyle is the Mediterranean diet.