Intake of ruminant trans fatty acids and changes in body weight and waist circumference

Follow-up studies have suggested that total intake of trans fatty acids (TFA) is a risk factor for gain in body weight and waist circumference (WC). However, in a cross-sectional study individual TFA isomers in adipose tissue had divergent associations with anthropometry. Our objective was to investigate the association between intake of TFA from ruminant dairy and meat products and subsequent changes in weight and WC. Furthermore, potential effect modification by sex, age, body mass index and WC at baseline was investigated.

Data on weight, WC, habitual diet and lifestyle were collected at baseline in a Danish cohort of 30,851 men and women aged 50-64 years. Follow-up information on weight and WC was collected 5 years after enrolment. The associations between intake of ruminant TFA (R-TFA) and changes in weight and WC were analysed using multiple linear regression with cubic spline modelling.

Intake of R-TFA, both absolute and energy-adjusted intake, was significantly associated with weight change. Inverse associations were observed at lower intakes with a levelling-off at intakes >1.2 g/day and 0.4 energy percentage (E %). Absolute, but not energy-adjusted, intake of R-TFA was significantly associated with WC change. An inverse association was observed at lower intakes with a plateau above an intake of 1.2 g/day.

The present study suggests that intake of R-TFA is weakly inversely associated with changes in weight, whereas no substantial association with changes in WC was found.