2026

Introduction: Body mass index (BMI) fluctuation has adverse health consequences, yet its determinants remain poorly understood. We examined genetic and environmental influences on BMI fluctuation and its associations with BMI trajectories. Data and methods: Data from 14 longitudinal twin cohorts, including 58 311 individuals (54% women) and 22 714 complete twin pairs (9761 monozygotic), were pooled. BMI […]

Although genetic and environmental factors play a key role in the long-term stability of anxiety, the extent to which the genetic and environmental determinants are best characterized by state- versus trait-like components is unclear. Also unclear is whether the genetic and environmental effects underlying trait and state components of anxiety differ across adult development. This […]

Introduction: Educational attainment (EA) is negatively associated with body mass index (BMI), but less is known about the association between EA and adult BMI change. We analysed the role of genetic and environmental factors in the associations between EA and BMI trajectory components over adulthood. Data and methods: Pooled data from 59,490 twins aged 31-99 years (49% […]

Introduction: Genetic and environmental factors contribute to weight gain, but how these effects change over adulthood is largely unknown. We examined how genetic factors influence BMI changes from young adulthood to old age and how this change relates to BMI in early adulthood. Data and methods: Data from 16 longitudinal twin cohorts, including 111,370 adults (56% women) […]

Obesity is a chronic disease that develops via complex interactions between human biology and the obesogenic environment. This study aimed to develop a high-resolution index of combined obesogenic neighborhood exposures in the U.S. and examine its association with body mass index (BMI), independent of familial factors shared by twins (e.g., genetics and early life environment). […]