Comparison of high and low trans-fatty acid consumers: analyses of UK National Diet and Nutrition Surveys before and after product reformulation

Objective: The WHO encourages the virtual elimination of artificial trans-fatty acids (TFA), which increase CHD risk. Our UK analysis explores whether voluntary reformulation results in differential TFA intakes among socio-economic groups by determining characteristics of high TFA consumers before and after product reformulation.

Design: Food intake was collected by 7d weighed records pre-reformulation and 4d diaries post-reformulation. Sociodemographic characteristics of TFA consumers above the WHO limit, and of the top 10 % of TFA consumers as a percentage food energy, were compared with those of lower TFA consumers. Multivariate logistic regression determined independent socio-economic predictors of being a top 10 % consumer.

Subjects: UK National Diet and Nutrition Surveys (NDNS) for adults aged 19-64 years pre-reformulation (2000/01; N 1724) and post-reformulation (2010/11-2011/12; N 848).

Results: Post-reformulation 2·5 % of adults exceeded the WHO limit, v. 57 % pre-reformulation. In unadjusted analyses, high TFA consumption was associated with lower income, lower education and long-term illness/disability pre- but not post-reformulation. In adjusted pre-reformulation analyses, degree holders were half as likely as those without qualifications to be top 10 % consumers (OR=0·51; 95 % CI 0·28, 0·92). In adjusted post-reformulation analyses, those with higher income were 2·5-3·3 times more likely to be top 10 % consumers than lowest income households. Pre-reformulation, high consumers consumed more foods containing artificial TFA, whereas ruminant TFA were more prominent post-reformulation.

Conclusions: High TFA consumption was associated with socio-economic disadvantage pre-reformulation, but evidence of this is less clear post-reformulation. Voluntary reformulation appeared effective in reducing TFA content in many UK products with mixed effects on dietary inequalities relating to income and education.