BACKGROUND: Childhood adversity has previously been associated with overweight and obesity in adult life, but there is a need for larger population-based studies using prospectively obtained adversity trajectories across childhood to confirm these associations. Moreover, childhood adversity may also be associated with underweight, which is less often studied. The aim of the current study is to investigate the association between childhood adversity trajectories from 0-15 years with weight categories in young adult men.

METHODS: The Danish Life Course Cohort (DANLIFE) was linked with the Danish Conscription Registry resulting in a study sample of 359,783 men, who have been assigned to one of five previously identified adversity trajectories from 0-15 years: "low adversity", "early material deprivation", "persistent material deprivation", "loss or threat of loss", and "high adversity". Height and weight in young adulthood was assessed at a draft board examination at age 18-26 years. Associations of adversity trajectories and weight categories were investigated in multinomial regression models.

RESULTS: Compared with the "low adversity" group, the four other adversity groups had higher risks of underweight, overweight, and obesity. The "high adversity" group showed the strongest associations with both underweight (1.44 (1.32, 1.58)) and obesity (1.50 (1.39, 1.61)) when adjusted for parental origin, birth year, age at draft board examination, and maternal age.

CONCLUSION: Childhood adversity, experienced between 0 and 15 years of life, was associated with a higher risk of underweight, overweight, and obesity in young adulthood among men.