Body Mass Index and Risk of Post-Traumatic Stress Disorder: A Cohort Study of 1.4 Million Late Adolescents.

INTRODUCTION

To assess whether abnormal body mass index (BMI) among Israeli Defense Force (IDF) recruits is associated with increased risk for post-traumatic stress disorder (PTSD).

MATERIALS AND

METHODS

This retrospective cohort study included 1,430,118 Israeli late adolescents aged 16-20 who were physically and mentally evaluated before IDF enlistment from January 1, 1998, to December 31, 2019. Body mass index was measured before enlistment, and PTSD diagnoses were based on the DSM-5 criteria as recorded by the IDF or the Ministry of Defense for combat-related PTSD. Individuals with PTSD diagnosis before recruitment were excluded.

RESULTS

Of the 1,430,118 late adolescents in this study, 839,200 (58.7%) were male, 1,329,796 (93.1%) were Jewish, and 392,418 (27.5%) served in combat roles. Post-traumatic stress disorder was diagnosed in 7,157 (0.5%) individuals. No significant association was found between BMI and PTSD risk in combat setting. However, late adolescents with prior psychiatric diagnoses exhibited an elevated PTSD risk: 40% higher in combatants (odds ratio [OR] = 1.366) and 30% higher in non-combatants (OR = 1.296). Furthermore, extreme BMI values (below 17 or above 35) in non-combat roles were associated with a lower PTSD risk.

CONCLUSIONS

In the largest cohort study to date on the association between BMI and PTSD because of combat, BMI did not significantly predict PTSD risk in combat-exposed soldiers, while psychiatric history emerged as a stronger predictor across all military roles. These findings suggest prioritizing mental health history over BMI in PTSD risk assessment and prevention efforts.