Effect of intentional weight loss through dietary intervention on cognition: The MIND Trial Study

Abstract Background With the increasing prevalence of obesity and its negative consequences on health, weight management has emerged as a priority for public health. We conducted a study to investigate the association of intentional weight loss through dietary intervention on cognition among older adults participating in the MIND trial. Method MIND trial enrolled overweight older adults aged 65‐85 years with a family history of dementia but without cognitive impairment and self‐reporting a suboptimal diet. Participants were randomized to the MIND diet or a control (usual) diet for 3 years; both diets promoted weight loss through mild caloric restriction. Of 604 individuals enrolled in the MIND trial, 520 had measured weight at the baseline and year 3 visit and were included in the analysis. We computed the percentage of weight loss based on baseline and last assessment and grouped individuals into 4 categories: weight gainers, <5% weight loss, 5‐10% weight loss, and >10% weight loss. Linear mixed‐effect models were used to estimate the 3‐year change in global cognitive scores. Models were adjusted by age, sex, race, apolipoprotein E (APOE) e4 allele, baseline BMI, and dietary assignment. Result The mean age was 70 years, 65% were women, and the mean BMI was 34 kg/m 2 . During 3 years of dietary intervention, 78.5% of participants lost weight. The average weight loss ranged from 2.3 kg to 15kg. Compared to people who gained weight, those with >10% weight loss significantly improved their cognitive scores by 0.103 SD/units (95%CI 0.008, 0.199) at year 3 visit. In addition, individuals who lost weight had improved plasma levels of inflammation, lipids, and glucose during the trial period. Among people in the MIND diet group, those with >10% weight loss significantly improved their cognitive scores by 0.171 SD/units (95%CI 0.028, 0.314) compared to people who gained weight; there was no significant association in the control diet group. Conclusion Among overweight and cognitively unimpaired individuals at the baseline with a family history of dementia, a weight loss of 10% (average 15 kg) or more during 3 years of dietary interventions was associated with improved cognitive scores when compared to people who gained weight.