This study aimed to investigate the effects of maternal unhealthy nutrition on the reproductive functions of female and male adult offspring. This was an animal study carried out with 24 virgin female Wistar rats (dams) and their male and female offspring. Rats were divided standard diet (SD) or cafeteria diet (CD) groups, after 10 weeks of feeding, all rats were paired with a Wistar stud male, and each group was again divided into CD and SD groups during the pregnancy and lactation periods. After birth, six female and six male pups in each group, were subjected to study. Following 3 weeks of lactation, the pups were fed with SD for 8 weeks and killed when they were considered adult at 11th week for analysis. Primordial and antral follicle counts, serum anti-Mullerian hormone (AMH) and phosphatase and tensin homolog (PTEN) in the oocyte cytoplasm were examined to evaluate ovarian function, and E-cadherin and integrin-β1 levels were examined in endometrial tissues for the evaluation of endometrial receptivity in female offspring. Sperm analysis was performed in male offspring. In groups in which the dams were fed CD, primordial follicular pool, PTEN, and endometrial receptivity were reduced. In contrast, AMH and the number of antral follicles were not changed. In male offspring, the testicles were smaller, testosterone production decreased, AMH increased and the number and function of sperm were not changed. Sperm analysis results were not changed. All negative effects on reproductive functions were more apparent in groups fed with the CD during the pregestational period.