Cognitive effects of adding caloric restriction to aerobic exercise training in older adults with obesity

OBJECTIVE: This study examined the short and long-term effects of adding caloric restriction to five months of aerobic exercise training on executive function in sedentary older adults with obesity. METHODS: Sedentary years adults with obesity aged 65–79 completed a randomized trial investigating the cardiorespiratory benefits of adding moderate (~250kcal) or high (~600kcal) caloric restriction to a 20-week aerobic exercise program. Approximately half (n=88) completed a cognitive assessment battery at baseline, post-intervention, and 18–24 months after intervention completion. The primary outcome was an executive function composite score. RESULTS: In the overall sample, the executive function composite increased 0.114 from baseline to post-intervention (p=0.01). Randomization to caloric restriction did not significantly alter executive function over aerobic exercise alone, nor were there between-group differences on any individual executive function test at post-intervention or long-term follow-up. Adding caloric restriction to exercise was associated with a modest increase in MMSE score (p=0.04). In the overall sample, increases from baseline at long-term follow-up were noted in digit symbol and word list recall performance as well. CONCLUSIONS: Adding caloric restriction to a 20-week aerobic exercise program does not worsen or improve executive function more than exercise alone assessed up to 24 months post-randomization.