Dietary pattern adherence in association with changes in body composition and adiposity measurements in the UK Biobank study

Background: Unhealthy dietary patterns (DP) have been frequently linked to avoidable ill-health, mediated in part through higher body mass index. However it is unclear how these patterns relate to specific components of body composition or fat distribution, and whether this may explain reported gender differences in the relationship between diet and health. Methods: Data from 101,046 UK Biobank participants with baseline bioimpedance analysis and anthropometric measures and dietary information on two or more occasions were used, of which 21,387 participants had repeated measures at follow up. Multivariable linear regressions estimated the associations between DP adherence (categorised in quintiles Q1-Q5) and body composition measures adjusted for a range of demographic and lifestyle confounders. Results: After 8.1 years of follow-up, individuals with high adherence (Q5) to the DP showed significantly positive changes in fat mass (mean, 95 % CI): 1.26 (1.12-1.39) kg in men, 1.11 (0.88-1.35) kg in women vs low adherence (Q1) 0.09 (-0.28 to 0.10) kg in men and 0.26 (-0.42 to 0.11) kg in women; as well as in waist circumference (Q5): 0.93 (0.63-1.22) cm in men and 1.94 (1.63, 2.25) cm in women vs Q1 1.06 (-1.34 to 0.78) cm in men and 0.27 (-0.02 to 0.57) cm in women. Conclusion: Adherence to an unhealthy DP is positively associated with increased adiposity, especially in the abdominal region, which may help explain the observed associations with adverse health outcomes.