Abstract: Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in young
reproductive-aged women. PCOS is often associated with obesity and impairs reproductive health.
Even though several theories have been proposed to explain the pathogenic mechanism of PCOS, the
role of insulin resistance (IR) as a key etiological component, independently of (but amplified by)
obesity, is well recognized. The consequent hyperinsulinemia activates excessive ovarian androgen
production, leading to PCOS. Additionally, the state of chronic inflammation related to obesity
impacts ovarian physiology due to insulin sensitivity impairment. The first-line treatment for
adolescents with obesity and PCOS includes lifestyle changes; personalized dietary interventions;
and, when needed, weight loss. Medical nutrition therapy (MNT) and the use of specific food
supplements in these patients aim at improving symptoms and signs, including insulin resistance
and metabolic and reproductive functions. The purpose of this narrative review is to present and
discuss PCOS in adolescents with obesity, its relationship with IR and the role of MNT and food
supplements in treatment. Appropriate early dietary intervention for the management of adolescents
with obesity and PCOS should be considered as the recommended approach to restore ovulation and
to protect fertility.
Keywords: polycystic ovary syndrome; fertility; obesity; adolescents; nutrition; diet; food supplements