Background: Unintentional weight loss in older people has been linked to increased risk of mortality. We aimed to investigate common medical conditions and lifestyle factors, including body fat distribution, as potential determinants of recent and prospective unintentional weight loss in early old age.
Methods: From the Medical Research Council (MRC) National Survey of Health and Development (NSHD), we included a total of 2234 study members aged 60-64 with information on unintentional weight loss in 2006-2010. Of these, 2136 also had information on unintentional weight loss recorded in 2015. Logistic regression was conducted to examine the associations between medical conditions, lifestyle, and body fat distribution at age 60-64 and unintentional weight loss at age 60-64 and 69.
Results: A total of 109 of 2234 study members had unintentional weight loss at ages 60-64, and 166 of 2136 at age 69. Never smoking was associated with lower risk of unintentional weight loss at age 60-64 (OR = 0.29, 95%CI = 0.12-0.68 compared to current smokers), and this association remained when adjusted for other determinants. Greater waist-hip ratio (OR = 0.95, 95%CI = 0.91-0.99) and body fat-lean mass ratio (OR = 0.96, 95%CI = 0.94-0.99) were associated with less likelihood of unintentional weight loss at age 60-64. Never smoking and greater hip circumference at age 60-64 were associated with lower odds of unintentional weight loss at age 69.
Conclusions: Smoking status and body fat distribution may help identify those at risk of unintentional weight loss in early old age. Their benefit in interventions to prevent age-associated weight loss needs to be further investigated.