Different body components associate differently with diet quality and physical activity in men and in women: a cross-sectional analysis

Background/objectives While the association between food quantity and obesity is well studied, the impact of diet components on specific body compartments is less well understood. Furthermore, there seem to be sex differences in the metabolism of different foods and the response towards physical activity (PA). Methods We investigated the association between diet components using a food frequency questionnaire, and body composition using bioimpedance analysis. We assessed data from 2021 of a cohort study of the Swiss general population, including 435 persons of both sexes (age range of 19–84 years). We used multivariable linear regression models separated by sex to assess the association between body composition (body mass index (BMI), skeletal muscle mass index (SMI), fat mass index (FMI), and visceral fat (VAT)), and diet quality and PA. Age, education, and place of residence were included as potential confounders. Results For both sexes, age showed the strongest positive association with FMI and VAT, while PA was negatively associated, especially in men. In men PA was also associated with BMI (not in women). Diet quality showed associations with body composition measures in women (not in men). In women, meat consumption was positively associated with SMI and FMI (not in men). In men fruits and wholegrain foods were negatively associated with FMI. VAT was negatively associated with fruits in women, and with fruits and wholegrain foods in men. Conclusion Our results are in line with evolutionary hypotheses on sex specific energy allocation and might contribute to more precise diet recommendations.