Background/Objective: The aim of this study was to outline the relationships between selected parameters connected with lifestyle and serum anti-Müllerian hormone (AMH) levels, i.e., a marker of ovarian reserve. By examining AMH levels in connection with nutrient intake and body composition parameters, this study aimed to provide a preliminary background for further studies focused on establishing dietary and lifestyle recommendations that could lead to improvements in fertility outcomes. Methods: The research involved 28 women, aged 26 to 42—both with and without ovulatory infertility—who were patients of the Reproductive Health Clinic at the Medical University of Białystok. The participants underwent a number of tests consisting of hormonal profiling, including AMH measurements, body composition analyses, and dietary assessments based on a 3-day food diary. Results: The findings of the study indicate that certain lifestyle factors are associated with changes in AMH levels. Most importantly, the multivariate linear regression model designed in the study shows that age, waist-to-hip ratio (WHR), as well as the intake of sucrose, iodine, and erucic acid explain variations in serum AMH levels. These results support the hypothesis that modifiable lifestyle factors can influence AMH levels, and thus ovarian reserve. Conclusions: The study underscores the potential for targeted lifestyle interventions to support fertility and calls for further research in the form of prospective studies performed in larger groups of patients to substantiate these associations and inform fertility care strategies. Based on the preliminary results of this study, certain dietary ideas that could positively influence fertility have been proposed, focused on the normalization of body weight and the reduction in excess fat tissue.