Long-Term Effects of Randomization to a Weight Loss Intervention in Older Adults: A Pilot Study

Abstract

Randomized, controlled trials (RCTs) show intentional weight loss improves body composition and physical function in older adults; however, the long-term benefits (and risks) are unknown. We conducted a pilot study to assess the feasibility of recalling prior RCT participants to examine the long-term effects of intentional weight loss on body composition and physical function. A weighted, random sample of 60 older adults who were randomized to caloric restriction plus exercise (CR + EX) or exercise (EX) only in 5 prior RCTs (mean age at randomization, 67.3 years; 69% women, 80% white) were invited to participate. Follow-up was obtained on 89% (42 clinic visits, 10 phone interviews, 1 death) an average of 3.5 years (range, 2.2–5.8 years) after RCT completion. Despite greater weight, fat and lean mass loss during the RCT (mean difference in change (95% CI): −4.19 (−7.52, −0.86), −2.75 (−5.10, −0.40), and −2.32 (−3.69, −0.95) kg, respectively) in those randomized to CR + EX, long-term changes in weight (2.05 (−2.35, 6.45) kg) and body composition (1.80 (−1.56, 5.17) and 0.03 (−2.20, 2.26) kg for fat and lean mass, respectively) from baseline and physical function at long-term follow-up (mean difference in 400-m walk and SPPB (95% CI): 23.2 (−19.3, 65.6) sec and −0.03 (−1.02, 0.96) points, respectively) were similar in CR + EX and EX only. Although improvements in weight and body composition following intentional weight loss may not be sustained long-term, physical function does not appear to be negatively impacted. A larger study is needed to confirm these results.