Childhood Obesity as a Predictor of Adult Physical/Functional Mobility; a Protocol for Systematic Review and Meta-Analysis.

Introduction

Childhood and adolescent overweight and obesity represent a significant global health concern. Prevalence estimates are variable across different countries and regions, typically indicating an upward trend over the past four decades^7–10. The global prevalence of childhood obesity was 5% in 2015, affecting almost 108 million children¹¹. The Global Atlas on Childhood Obesity observed a 1.5-fold increase in obesity prevalence between 2012 and 2023 compared to the period from 2000 to 2011¹². It has also been reported that the increasing trend in childhood and adolescent obesity has yet to stabilise¹³. Projections estimate that 158 million individuals aged 5 to 19 years of age would be affected by obesity in 2020, increasing to 254 million by 2030¹².

Furthermore, when examined by geographical region, the occurrence of obesity among children and adolescents was highest in Polynesia (19%), followed by the Caribbean (19%), North America (17%), Central America (16%), and Western Asia (10%). In Europe, the incidence of childhood and adolescent obesity was greatest in Southern Europe (8%), followed by Eastern Europe (5%), Northern Europe (5%), and Western Europe (4%)¹⁴. The literature indicates an inverse relationship between socioeconomic status and childhood obesity, with higher obesity prevalence (age range 5–19 years) among boys (8%) compared to girls (6%) in upper-middle and high-income countries^15–17. The growing burden of childhood obesity has resulted in escalating costs for individuals, society and national exchequers¹⁸.

Obesity arises from a complex interplay of biological, genetic, behavioural, and environmental factors, with sub-optimal nutrition and sedentary lifestyle as key contributors^19–21. Evidence suggests that low parental education levels, lower household income, limited participation in the labour market, and poor family conditions contribute to sub-optimal nutrition and fewer opportunities for play and physical activity among children and adolescents, which can influence the development of obesity^22–24. Childhood obesity can lead to both short and long-term health complications such as hypertension, cavities and periodontal disease, reduced physical function, asthma, sleep apnoea, impaired glucose tolerance, metabolic dysfunction and constipation¹. Furthermore, it has been demonstrated that childhood overweight/obesity frequently persist into adulthood²⁵, Obesity, being a disease in its own right, presents significant management challenges, particularly when it coexists with other conditions, such as psychological disorders, neurological disability, or inflammatory disease²⁶. Observed adverse outcomes in adulthood as a result of childhood overweight/obesity include an elevated risk and earlier onset of chronic diseases such as CVD, obesity in adults, Type 2 diabetes, anxiety, depression, physical or functional impairments, renal disorders, and certain cancers^{3–6,25,27–31}.

A systematic review on obesity tracking across the lifespan reported that approximately 55% of children with obesity have obesity in adolescence. In addition, 80% of adolescents with obesity continue to live with obesity into adulthood, and nearly 70% live with obesity beyond age 30⁵. Several systematic reviews indicated that childhood obesity is an independent risk factor for hypertension, dyslipidaemia, carotid artery atherosclerosis, insulin resistance, metabolic syndrome, premature mortality, and cardiovascular disease (CVD) in adulthood^6,32–35. In addition, a systematic review published in 2017 reported a significant positive association between childhood obesity and adult systolic blood pressure, diastolic blood pressure, and triglyceride levels, along with a significant inverse association with adult high-density lipoprotein (HDL) cholesterol. Furthermore, these associations were reversed in studies that adjusted for adult body mass index (BMI), suggesting that adult BMI may act as a mediator of CVD².

Gallagher et al.,²⁸ reported that increasing adiposity from childhood to adulthood is linked to a heightened risk of depression, particularly among women. Another recent review found that children with an average increase in BMI (OR = 2.24) and those with persistently elevated BMI (OR = 2.64) had higher odds of experiencing depression in middle-age compared to individuals with a consistently average BMI trajectory²⁹. In essence, those with a persistently high BMI from childhood through mid-adulthood, as well as those whose BMI rose from average levels in childhood to higher levels in adulthood, were at greater risk of depression in middle-age. Encouragingly, improving childhood adiposity profile by adulthood was linked to a reduction in anxiety symptoms²⁹.

Additionally, a 2023 systematic review and meta-analysis³ found that childhood obesity raised the risk of cancer incidence and mortality in adulthood by 33% and 28%, respectively. Subgroup analysis by sex revealed higher hazard ratios in males compared to females (HRs) for cancer incidence (20% vs. 39%) and mortality (20% vs. 40%)³.

Moreover, a systematic review by Pourghazi, Farzad, and colleagues identified a significant positive association between elevated BMI in early life and an increased risk of renal disease later in life⁴. In summary, there is strong evidence that childhood obesity is associated with increased risk of chronic disease and mental health difficulties later in life. However, there is a dearth of data regarding the relationship between childhood obesity and musculoskeletal health and physical function in adulthood.

Functional movement refers to body movements characterised by proper joint and muscle function and efficient movement patterns, which reduce injury risk^36,37, and is considered a foundation for more complex forms of movement³⁸. Assessments of functional movement typically measure postural control, stability, flexibility, neuromuscular coordination, and balance^36,37,39. These components not only support complex efficient movement but are also linked to key health indicators and activities of daily living (e.g. falls, sitting and standing, functional independence etc.)^40–43. To reduce disability, enhance quality of life, and mitigate social and economic consequences, it is essential that musculoskeletal health is prioritised and addressed⁴⁴. Children with obesity were found to have a higher incidence of fractures, lower extremity malalignment and musculoskeletal pain compared to their normal-weight peers⁴⁵. Additionally, Thivel, et al.⁴⁶ report that children and adolescents with obesity exhibit reduced muscular fitness and strength compared to their healthy weight peers, primarily due to extreme body weight and bodily inertia. Additionally, a 2022 systematic review by O’Brien, Wesley, et al.,⁴⁷ identified a negative association between childhood obesity and functional mobility in children and adolescents. Regarding the risk of adult mobility impairment, a review by Yuan, and colleagues⁴⁸ revealed that obesity in adulthood is linked to an elevated risk of frailty (functional mobility impairment) in community-dwelling older adults. A 2012 study by Wills, et al.,⁴⁹ reported a strong positive association between obesity and musculoskeletal conditions, particularly osteoarthritis (OA) and in 2015, Antony et al.,³⁰ reported a significant positive association between childhood overweight and adult knee joint pain, stiffness and dysfunction in adult males (even when no longer living with overweight). This suggests that childhood overweight/obesity may contribute to knee abnormalities later in life and is supported by work exploring the impact of obesity on lower limb biomechanics and development⁵⁰. Additionally, in 2018, Meng et al., found that childhood adiposity results in ongoing patellar stress and structural anomalies in adults, indicating lasting consequences of excess weight during early life on knee development and health³¹. Given that the musculoskeletal system and biomechanic alignment of the lower limbs develops and matures during childhood and adolescence it is important to consider and address factors that might influence sub-optimal musculoskeletal development impacting adult musculoskeletal health, fitness and function. Therefore, following clinical guidelines by monitoring obesity development and providing access to early intervention during childhood is essential for longer-term health outcomes^51,52.

The literature indicates that childhood and adolescent obesity contribute to various health complications in children, adolescents, young adults, and older adults. While reviews have explored the link between childhood obesity and adult cardio-metabolic complications, a significant gap remains in understanding the impact of childhood overweight/obesity on adult musculoskeletal health, physical function or mobility. Specifically, it is unclear whether childhood obesity directly affects musculoskeletal health and/or physical mobility in adulthood, whether there is an association between the two, and if so, whether factors like age at obesity onset, stage of obesity, type of obesity, access to treatment, type of treatment received or sociodemographics are important factors to consider. To enhance the evidence base, we will undertake a systematic review and meta-analysis to determine whether childhood overweight/obesity is associated with musculoskeletal health, physical function or mobility in adulthood. This review will focus on determining whether childhood overweight/obesity constitutes an independent predicator of impaired musculoskeletal health, physical function or mobility in adulthood.

Objectives

Methods

A systematic review and meta-analysis of the current literature will be conducted. This protocol follows the PRISMA-P guidelines⁵⁷ (see supplemental file 1).

Results

This systematic review is expected to be finalised by the end of June 2025. The results of this review will be organised into several subsections: Study selection (reported with PRISMA flowchart) and characteristics (synthesized and reported with tabular data), 2) study results and outcomes (including correlations between childhood obesity and functional and physical mobility in adulthood, and unadjusted and adjusted risk associated with childhood overweight/obesity and with impaired musculoskeletal health, physical function or mobility in adulthood.

Discussion

This systematic review will investigate the link between childhood overweight/obesity and musculoskeletal health, physical function health in adults, identifying factors contributing to their impact on adult mobility. This will guide targeted interventions and preventive measures, focusing on childhood factors and treatments to support long-term adult mobility and musculoskeletal health. This will provide an evidence base upon which early interventions can be developed to Maximise adult physical health and function.

Ethics and consent

Ethical approval and consent were not required for this protocol.