Impact of Diet and Exercise on Weight and Cognition in Older Adults: A Rapid Review

Objective: To determine where the current literature stands in regard to diet/exercise interventions on cognition in overweight or obese individuals. Data Source: A rapid review was conducted of English-language studies published in Medline from January 1965 to January 2020. Study Inclusion and Exclusion Criteria: Included studies were intervention studies lasting ≥12 weeks, with participants aged ≥65 years, with a body mass index ≥25 kg/m2 Data Extraction: Data extracted included study population, duration, intervention design, outcomes, and results. Data Synthesis: Outcomes were qualitatively measured due to paucity of RTC. Results: 1845 citations were identified, 31 full-text articles were reviewed, and 5 studies were included. Studies had usual care control groups and combined exercise/diet intervention groups with 31-3,526 participants randomized to each arm. Mean age of participants was 69.2-83.4 years. Studies reporting on cognitive changes showed marginally significant positive changes in cognition, and those that reported BMI indicated potential improvements in cognition. Conclusions: The number of interventions assessing the combined effects of both diet and exercise is low. Future studies should evaluate the impact of combined effects to ascertain whether cognitive decline may be reversed in older adults with a BMI ≥25 kg/m2.