Prevalence and determinants of self-reported low-fat-, low-salt-, and vegetarian diets in patients with cardiovascular disease between 1996 and 2019

Background and aims: Guidelines no longer recommend low-fat diets and currently recommend more plant-based diets to reduce atherosclerotic cardiovascular disease (ASCVD) risk. Furthermore, these guidelines have consistently recommended salt-reduced diets. This article describes current self-reported use and time-trends in the self-reported use of low-fat, low-salt and vegetarian diets in ASCVD patients and examines patient characteristics associated with each diet. Methods and results: 9005 patients with ASCVD included between 1996 and 2019 in the UCC-SMART cohort were studied. The prevalence of self-reported diets was assessed and multi-variable logistic regression was used to identify the determinants of each diet. Between 1996-1997 and 2018–2019, low-fat diets declined from 22.4 % to 3.8 %, and low-salt diets from 14.7 % to 4.6 %. The prevalence of vegetarian diets increased from 1.1 % in 1996–1997 to 2.3 % in 2018–2019. Patients with cerebrovascular disease (CeVD) and peripheral artery disease or an abdominal aortic aneurysm (PAD/AAA) were less likely to report a low-salt diet than coronary artery disease (CAD) patients (OR 0.62 [95%CI 0.49–0.77] and 0.55 [95%CI 0.41–0.72]). Conclusion: In the period 1996 to 2019 amongst patients with ASCVD, the prevalence of self-reported low-fat diets was low and decreased in line with changes in recommendations in major guidelines. The prevalence of self-reported vegetarian diets was low but increased in line with societal and guideline changes. The prevalence of self-reported low-salt diets was low, especially in CeVD and PAD/AAA patients compared to CAD patients, and decreased over time. Renewed action is needed to promote low-salt diets in ASCVD patients.