Obesity in the UK Armed Forces: risk factors.

OBJECTIVE To assess the risk factors of obesity in terms of body mass index (BMI) and waist circumference in the UK Armed Forces. METHODS A quota sample from all UK services, of 2,448 men and 311 women aged 17-55 years. RESULTS The risk ratios for those with a BMI 227.5 kg/m2 and waist circumference 294 cm in men were 0.21 (95% confidence interval [CI], 0.13-0.34) for non-whites compared to whites, 0.55 (95% CI, 0.38-0.78) for commissioned officers compared to lower ranks, and 0.13 (95% CI, 0.06-0.31) for Royal Marines compared to the Army, but increased with age, 58.2 (95% CI, 19.6-172.7). Risk ratios were usually nonsignificant between service-demographic factors for BMI > or = 27.5 kg/m2 and waist circumference < 94 cm. CONCLUSIONS The risk of obesity is highest in the Army and Royal Navy, whites, lower ranks, and older ages. BMI and waist circumference should be used together as measures of obesity.