Background: Although overweight and obesity are less prevalent among active-duty military personnel compared with similar persons not serving in the military, no such differences have been observed between veterans and non-veterans.
Objectives: To assess the magnitude of weight changes before, concurrent with and following discharge from the military, relative to weight during service, and to determine the demographic, service-related and psychological characteristics associated with clinically important weight gain among those who were discharged from military service during follow-up.
Methods: Eligible Millennium Cohort Study participants (n=38 686) completed the questionnaires approximately every 3 years (2001, 2004 and 2007) that were used to estimate annual weight changes, as well as the percentage experiencing clinically important weight gain, defined as 10%. Analyses were stratified by sex.
Results: Weight gain was greatest around the time of discharge from service and in the 3 years before discharge (1.0-1.3 kg per year), while it was nearly half as much during service (0.6-0.7 kg per year) and 3 years after service ended (0.7 kg per year). Consequently, 6-year weight gain was over 2 kg greater in those who were discharged compared with those who remained in the military during follow-up (5.7 vs 3.5 kg in men; 6.3 vs 4.0 kg in women). In those who were discharged, younger age, less education, being overweight at baseline, being in the active-duty component (vs Reserve/National Guard) and having experienced deployment with combat exposures (vs non-deployment) were associated with increased risks of clinically important weight gain.
Conclusions: This study provides the first prospectively collected evidence for an increased rate of weight gain around the time of military discharge that may explain previously reported higher rates of obesity in veterans, and identifies characteristics of higher-risk groups. Discharge from military service presents a window of risk and opportunity to prevent unhealthy weight gain in military personnel and veterans.