The American Journal of Human Biology (AJHB), the flagship journal of the Human Biology Association, has published research on human biology, health, and disease since 1989. The goal of this study is to identify the dominant research themes published in the journal and track their evolution over this 36-year period. To achieve this goal, we adopted a mixed-methods approach that combined large language model (LLM) topic modeling, using Bidirectional Encoder Representations from Transformers (BERT), with qualitative expert review. Our dataset comprised 3348 abstracts and metadata (e.g., author, year, title) published between 1989 and April 2025 retrieved from PubMed. We used BERT-based clustering as a first-pass classifier and then expert consensus to consolidate the clusters into themes. Fifteen major themes emerged. We then examined temporal changes in these 15 themes. Two themes that have and continue to dominate are Growth and Development and Body Composition. In contrast, Genetics, while common, declined in recent years. Maternal, Fetal, and Infant Health, and Demography and Reproduction, while always well-represented, increased, especially since 2010. Meanwhile, the less-prevalent themes Stress Biology, Nutrition, and Human Biology Frameworks have shown gradual growth. Overall, while a set of themes dominate the journal's corpus of scholarship, the trends we found indicate a transition toward more theory-driven analyses of health and disease and underscore the journal's responsiveness to emerging scientific paradigms and global health challenges, offering a roadmap for future scholarship.

This cross-sectional study examined the association between neighborhood social fragmentation and excessive body weight in childhood. The sample included 832 children aged 3-10 years living in the municipality of Porto, Portugal. Excessive body weight was classified using International Obesity Task Force sex- and age-specific cut-offs. Neighborhood social fragmentation was assessed using a composite index derived from 2021 Portuguese Census data at the statistical section level. Associations were estimated using sex-stratified multivariable logistic regression adjusted for relevant confounders. No association was observed between neighborhood social fragmentation and excessive body weight among boys. In contrast, girls living in the least fragmented neighborhoods had lower odds of excessive body weight compared with those in the most fragmented neighborhoods (OR = 0.55, 95% CI = 0.32-0.94, p = 0.030). These findings suggest that neighborhood social structure may be differently associated with childhood body weight by sex and may contribute to observed gender disparities in excess body weight among children.