The Mediterranean dietary pattern, where extra virgin olive oil (EVOO) takes the central spot, is related to longer life expectancy and lower risk of a number of non-communicable diseases, including cardiovascular, diabetes, dementias, and cancer. Positive effect of olive oil on a broad spectrum of diseases, including diabetes mellitus type 2 (DMT2), is usually attributed to its fatty acid content (e.g., oleic acid). Yet, in the last two decades researchers confirmed that, the phenolic compounds (e.g., oleuropein) also significantly alter on glycaemic regulation. Other unprocessed parts of olive plant (fruit and leaves) showed positive impact on glycaemic variability among individuals living with DMT2. The present review focuses on the available research findings on the effect of olive oil, fruits, and leaves on DMT2 treatment. Specifically, the focus is on polyphenols and fats of olive oil, fruits, and leaves with regard to their antidiabetic biological activities.

Epidemiological studies have reported an association between obesity/metabolic syndrome (MetS) and male reproductive disorders. Endocrine dysfunctions, direct testicular damage, chronic low-grade inflammation, and insulin resistance (IR) are involved in the occurrence of male obesity secondary hypogonadism (MOSH) which in turn alters the metabolic imbalance, creating a sort of vicious circle. Since IR and chronic inflammation state play a pivotal role in MOSH, low-calorie and low-carbohydrate diet protocols may be administered in obese men to improve their metabolic and hormonal profile. The ketogenic diet (KD) has been reported to determine positive effects on body weight, IR, cardio-metabolic risk, hypothalamic-pituitary-testicular (HPT) axis, and prostate with possible improvement of plasma androgens levels, sexual function (SF), and male fertility. This review aims to evaluate the effectiveness of KD on testicular function. Emerging evidence reports that very low-calorie KD (VLCKD) may revert MOSH by restoring HPT axis function and testosterone (T) levels. Moreover, VLCKD could improve SF, prostate health and lower urinary tract symptoms (LUTSs) in overweight/obese male patients. VLCKD may also positively impact spermatogenesis although evidence is still poor. Future studies are warranted to clarify the effectiveness of KD on testicular and prostate gland function.