You might be interested in…Childhood Obesity

Childhood obesity is a major public health problem worldwide due to its rapidly increasing prevalence, the increased risk of early-onset non-communicable diseases (NCDs), the reduced quality of life of the affected children and its implications for adulthood morbidity.

The global prevalence of obesity among children and adolescents aged five to 19 years has quadrupled in the last 41 years, with an estimated rate of increase in the age-standardised body mass index (BMI) of 0.32 kg/m2 per decade for boys and 0.40 kg/m2 per decade for girls. The prevalence of childhood obesity and its associated comorbidities is a growing global health problem that disproportionately affects populations in low- and middle-income countries (LMICs) and minority ethnicities in high-income countries (HICs).

The increased childhood obesity disparities among populations reflect two concerns: one is HICs’ ineffective intervention approaches in terms of lifestyle, nutrition and physical activity in minority populations, and the second is the virtually non-existent lifestyle obesity interventions in LMICs. This review article1provides guidelines on childhood obesity and its comorbidities in high-risk minority populations based on understanding the prevalence and effectiveness of preventative lifestyle interventions.

The authors highlight how inadequate obesity screening by body mass index (BMI) can be resolved by using objective adiposity fat percentage measurements alongside anthropometric and physiological components, including lean tissue and bone density. National healthcare childhood obesity prevention initiatives should embed obesity cut-off points for minority ethnicities, especially Asian and South Asian ethnicities within UK and USA populations, whose obesity-related metabolic risks are often underestimated.

Also, lifestyle interventions are underutilised in children and adolescents with obesity and its comorbidities. The authors argue that the overwhelming evidence on lifestyle interventions involving children with obesity comorbidities from ethnic minority populations shows that personalised physical activity and nutrition interventions are successful in reversing obesity and its secondary cardiometabolic disease risks.

Interventions combining cultural contextualisation and better engagement with families are the most effective in high-risk paediatric minority populations but are non-uniform amongst different minority communities. They conclude that sustained preventative health impact can be achieved through the involvement of the community, with stakeholders comprising healthcare professionals, nutritionists, exercise science specialists and policy makers.

What about the heritability of obesity? In this review,2 the authors explore the current understanding of the mechanisms mediating transgenerational and intergenerational transmission of obesity. They find that the heritability of obesity is estimated to range from between 40 per cent and 75 per cent. Genetic forms of obesity manifest along a continuum of clinical features traditionally classified into three overarching categories: Mendelian (monogenic) obesity, Mendelian non-syndromic obesity, and polygenic obesity.

Mendelian obesity forms result from rare chromosomal abnormalities and pathogenic gene variants that impact critical proteins involved in regulating energy balance. They are typically rare and early-onset. Polygenic obesity does not stem from a single gene with a significant impact on obesity development. Polygenic obesity is believed to be determined by the cumulative influence of numerous common genetic variants each exerting a modest effect. They conclude that more research is needed for better understanding of this complex area.

Another important factor in the aetiology of child obesity is the quality of the built environment. The authors of this review on the topic3 describe the built environment as including physical structures where children live, learn, eat, sleep, and play. Features of the built environment (eg, availability of parks and playgrounds) can influence children’s physical activity (PA) levels, diet, sleep, stress, and overall health including risk for obesity.

Neighbourhood level disparities in the built environment contribute to disparities in PA levels and risk for obesity seen in low-income communities and communities of colour. The authors conclude that while childhood obesity has long been recognized as multifactorial, only more recently has the medical literature experienced a paradigm shift to recognize the built environment as a key determinant of these outcomes.

A growing evidence base demonstrates the promise of policy and neighbourhood interventions to modify features of the built environment on improving childhood obesity outcomes. These range from healthy neighbourhood design that promotes walkability and access to parks, to classroom and community wide PA educational campaigns. See ‘Investing in roads is a backwards step…’ by Dr Catherine Conlon.

In another review,4 the authors describe how obesity as a systemic disease carries the risk of non-metabolic complications, such as cardiovascular diseases, polycystic ovary syndrome, chronic kidney disease, asthma, thyroid dysfunction, immunologic and dermatologic conditions, and mental health problems. These complications can affect almost all systems of the young body and also leave their mark in adulthood.

In addition, obesity also contributes to the exacerbation of existing childhood diseases. As a result, children suffering from obesity may have a reduced quality of life, both physically and mentally, and their life expectancy may be shortened. It also turns out that, in the case of obese pregnant girls, the complications of obesity may also affect their unborn children. This again underlines the importance of taking all necessary actions to prevent the growing epidemic of obesity in the paediatric population, as well as to treat existing complications of obesity and detect them at an early stage.

To accurately capture the effectiveness and cost-effectiveness of childhood obesity prevention interventions requires an understanding of the broader impacts (or spillover effects). This systematic review5 assesses the spillover effects of childhood obesity prevention interventions. The cautiously optimistic conclusion is that there is limited evidence of positive spillover effects of childhood obesity prevention interventions observed in parents/caregivers and families of targeted participants.

References:

1. Alkhatib A et al. Childhood Obesity and Its Comorbidities in High-Risk Minority Populations: Prevalence, Prevention and Lifestyle Intervention Guidelines. Nutrients 2024, 16, 1730. https://doi.org/10.3390/nu16111730
2. Sivakumar S et al. Childhood obesity from the genes to the epigenome. Front. Endocrinol. 15:1393250. doi: 10.3389/fendo.2024.1393250
3. Galvez M et al. The Built Environment and Childhood Obesity. Pediatric Clinics of North America Volume 71, Issue 5, October 2024, Pages 831-843. doi: 10.1016/j.pcl.2024.06.004
4. Ciez˙ki, S et al Not Only Metabolic Complications of Childhood Obesity. Nutrients 2024, 16, 539. https://doi.org/10.3390/nu16040539
5. Brown V et al. Spillover effects of childhood obesity prevention interventions: A systematic review. Obes Rev 2024 Apr;25(4):e13692. doi: 10.1111/obr.13692