An increasing number of studies highlight the critical role of both maternal and paternal nutrition and body weight before conception in shaping offspring health. Traditionally, research has focused on maternal factors, particularly in utero exposures, as key determinants of chronic disease development. However, emerging evidence underscores the significant influence of paternal preconception health on offspring metabolic outcomes. While maternal health remains vital, with preconception nutrition playing a pivotal role in fetal development, paternal obesity and poor nutrition are linked to increased risks of metabolic disorders, including type 2 diabetes and cardiovascular disease in children. This narrative review aims to synthesize recent findings on the effects of both maternal and paternal preconception health, emphasizing the need for integrated early interventions. The literature search utilized PubMed, UNF One Search, and Google Scholar, focusing on RCTs; cohort, retrospective, and animal studies; and systematic reviews, excluding non-English and non-peer-reviewed articles. The findings of this review indicate that paternal effects are mediated by epigenetic changes in sperm, such as DNA methylation and non-coding RNA, which influence gene expression in offspring. Nutrient imbalances during preconception in both parents can lead to low birth weight and increased metabolic disease risk, while deficiencies in folic acid, iron, iodine, and vitamin D are linked to developmental disorders. Additionally, maternal obesity elevates the risk of chronic diseases in children. Future research should prioritize human studies to explore the influence of parental nutrition, body weight, and lifestyle on offspring health, ensuring findings are applicable across diverse populations. By addressing both maternal and paternal factors, healthcare providers can better reduce the prevalence of metabolic syndrome and its associated risks in future generations.

Gestational obesity, defined as obesity during pregnancy or a pre-pregnancy BMI ≥30, is a growing global health challenge with profound implications for both maternal and offspring health. This narrative review synthesizes current evidence on the mechanistic pathways by which maternal obesity affects pregnancy outcomes and intergenerational health trajectories. For mothers, gestational obesity increases the risk of gestational diabetes, hypertensive disorders, cesarean delivery, and postpartum weight retention. Offspring exposed to maternal obesity face higher risks of obesity, metabolic syndrome, cardiovascular disease, and neurodevelopmental disorders, many of which persist across the lifespan. The underlying mechanisms include metabolic dysregulation, insulin resistance, chronic inflammation, oxidative stress, and alterations in placental function. Epigenetic modifications, such as DNA methylation, histone changes, and non-coding RNA expression, play central roles in fetal programming, while maternal gut dysbiosis and alterations in breast milk microbiota further shape infant health outcomes. Importantly, maternal obesity not only influences pregnancy and early life but also perpetuates an intergenerational cycle of obesity and related comorbidities. Preventive strategies targeting preconception and prenatal health, combined with interventions to optimize lactation and maternal diet, may mitigate long-term risks. Future research should prioritize longitudinal and mechanistic studies to refine interventions aimed at disrupting the transmission of obesity-related disease across generations.