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 5 months of aerobic exercise training on executive function in sedentary older adults with obesity. METHODS: Sedentary adults with obesity aged 65 to 79 years completed a randomized trial investigating the cardiorespiratory benefits of adding moderate (~ 250 kcal) or high (~ 600 kcal) caloric restriction to a 20-week aerobic exercise program. Approximately half (n = 88) completed a cognitive assessment battery at baseline, post intervention, and 18 to 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 postintervention (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 following the intervention or at long-term follow-up. Adding caloric restriction to exercise was associated with a modest increase in Mini-Mental State Examination 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.