Obesity, but not overweight, is associated with poorer working memory in women, according to study results published in Eating Behaviors.
The results indicated that this association did not exist in men with obesity.
The study included data from individuals interviewed during Wave 4 of the National Longitudinal Study of Adolescent to Adult Health (N=4769) who were not pregnant. The researchers looked at information on patient body mass index (BMI), sex, and working memory. Working memory was measured using the digit span backward task, with scores ranging from 0 to 7. Higher scores indicate better memory and a score of 4 or 5 is considered typical. The researchers also included age, race, total household income, education level, smoking status, alcohol use, physical activity, and illnesses as covariates.
Using analysis of variance (ANOVA) with sex and weight classification as factors, the researchers found that women with obesity (M =3.88; SE =0.05) showed worse working memory compared with both women with overweight (M =4.23; SE =0.06; P <.001) or normal weight (M =4.35; SE =0.05; P <.001).
However, the results did not indicate any significant differences between the working memory of overweight women compared with normal-weight women (P =.134).
In men, there were no differences in working memory in men with obesity (M =4.22; SE =0.05), overweight (M =4.29; SE =0.05), or normal weight (M =4.24; SE =0.06; P >.382).
After controlling for covariates, these effects were not altered.
The study had several limitations, including its cross-sectional design. The researchers also noted that they only used a single measure of working memory and that continued research on the subject should use other methods.
“Future research should be careful to consider sex as an important factor in the association between obesity and executive function,” the researchers wrote.
Yang Y, Shields GS, Wu Q, Liu Y, Guo C. Obesity is associated with poor working memory in women, not men: findings from a nationally representative dataset of U.S. adults. Eat Behav. 2019;35:101338.