Impact of BMI on childhood growth, pubertal timing, and bone maturation: A comprehensive review and clinical implications

Introduction: Childhood obesity and undernutrition significantly affect growth patterns, pubertal timing, and bone maturation, leading to long-term health implications.
Materials and Methods: A comprehensive literature review was conducted using databases such as PubMed, Google Scholar, and Scopus. Twenty-four studies, including a total of 40,732 patients, were analyzed from two tables examining the impact of BMI, growth patterns, pubertal timing, and bone maturation.
Results: Children with high BMI exhibit accelerated linear growth during early childhood, that may be driven by elevated leptin levels, which stimulate growth before puberty. Despite early growth advantages, these children experience reduced height gain during adolescence due to advanced bone maturation and earlier closure of growth plates. High BMI is strongly linked to early puberty, especially in girls, as increased adipose tissue raises leptin levels, triggering early pubertal onset. Boys, however, show variability in pubertal timing, with severe obesity sometimes delaying puberty.
In contrast, children with low BMI or undernutrition demonstrate delayed linear growth and delayed puberty. Nutritional deficits lead to reduced growth velocity, delayed pubertal onset, and extended pubertal periods due to a lack of adipose tissue and hormonal deficiencies in leptin and kisspeptin. Nutritional rehabilitation promotes catch-up growth, allowing for extended growth potential by delaying growth plate closure. However, full recovery may not occur in cases of prolonged or severe undernutrition. Advanced bone age in high BMI children shortens the pubertal growth spurt, while delayed bone maturation in undernourished children offers a prolonged period for potential growth, contingent on timely nutritional support.
Conclusion: Timely interventions for childhood obesity and undernutrition are critical to improving growth outcomes and preventing long-term developmental delays. Early identification, nutritional rehabilitation, and lifestyle modifications can help optimize growth and pubertal development by addressing both advanced and delayed growth trajectories.