Abstract / Summary
Childhood obesity has emerged as one of the most significant non-communicable disease challenges globally. The condition is associated with metabolic, cardiovascular, psychological, endocrine and social consequences extending into adulthood. The aetiology of childhood obesity is multifactorial and involves complex interactions between genetic susceptibility, epigenetic modifications, dietary transition, sedentary behaviour, environmental exposures, socioeconomic determinants and prenatal influences. Contemporary evidence suggests that the traditional calorie-centric explanation is insufficient to explain the rapid epidemiological transition. To systematically analyse the multidimensional aetiology of childhood obesity and identify the new and unique interactions among genetic, behavioural, prenatal, environmental, psychosocial and technological determinants contributing to childhood obesity. A systematic analytical review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Literature was searched from PubMed, EMBASE, Scopus, Web of Science and standard textbooks with ISBN references. Articles published between 2005 and 2026 in English were included. Keywords included ‘childhood obesity’, ‘aetiology’, ‘genetics’, ‘environment’, ‘screen time’, ‘prenatal determinants’ and ‘epigenetics’. After screening and eligibility assessment, relevant studies were narratively synthesised. The review demonstrated that childhood obesity originates from interconnected biological and environmental pathways. Strong associations were identified with parental obesity, maternal gestational weight gain, high-calorie processed foods, reduced physical activity, sleep deprivation, excessive screen exposure, socioeconomic disparities, urbanisation, endocrine-disrupting chemicals, gut microbiome alteration and genetic polymorphisms. New evidence highlights the importance of the ‘first 1000 days’, gene–environment interaction, digital lifestyle transition and epigenetic programming as major contributors. Machine-learning-based analyses also revealed multilevel predictive determinants. Childhood obesity is not a single-determinant disorder but a systems-level metabolic disease arising from cumulative biological and environmental insults beginning before birth. The new and unique finding of this study is the integrated model of prenatal programming, digital behavioural transition and gene–environment interaction as a unified explanatory framework for childhood obesity. This integrated understanding may facilitate precision prevention strategies and advance future medical science toward predictive and personalised paediatric metabolic care.