*2.2. Study Group and Data Collection*

The study group consisted of 5690 participants (2554 men and 3136 women) of the National Multicenter Health Survey II (the Polish acronym is WOBASZ II). WOBASZ II is a cross-sectional study representative of the Polish adult population aged 20 years and over, which was carried out by the National Institute of Cardiology (formerly the Institute of Cardiology), Warsaw, Poland, in the years 2013–2014, in collaboration with five national medical universities. The design and methods of the WOBASZ II survey have been described in detail elsewhere [38]. Daily food consumption data were collected by trained interviewers using a single 24-h dietary recall method. The overall evaluation included a sample of 6170 participants, 480 of whom were excluded due to missing or unreliable dietary recalls. A flowchart of the participants is shown in Figure 2. The WOBASZ II study was approved by the Bioethics Committee of the National Institute of Cardiology (no. 1344), as was the current study (no. 1837). Written informed consent was obtained from all participants.

**Figure 2.** Flow chart of the study participants.

Data on the demographic status, diseases, leisure-time physical activity, tobacco use, community size, marital status, and education level of the participants were collected using a standardized questionnaire developed for the WOBASZ II survey. Height and weight measurements were taken by personnel trained in standard procedures. Body mass index (BMI) was calculated from body weight in kilograms divided by the square of the height in meters. Blood pressure (BP) was measured three times on the right arm after 5 min of rest in a sitting position at 1 min intervals, and final BP was reported as the mean of the second and third measurements. The general characteristics of the study group are shown in Table 1.

The present study identified 361 dietary sources of plant sterols based on the consumption of foods and dishes reported by participants in the WOBASZ II survey. A small proportion of subjects who consumed phytosterol-enriched products was found (Table 1). Plant sterol daily intake was determined by multiplying the daily consumption of individual food items by the respective total plant sterols, such as the β-sitosterol, campesterol, and stigmasterol contents, in these food items and then summed up.


**Table 1.** General description of the studied population.

\* *<sup>p</sup>* calculated for differences between men and women. <sup>1</sup> Hypertension: systolic blood pressure SBP ≥140 mmHg or diastolic blood pressure DBP ≥90 mmHg, or use of antihypertensive drugs. <sup>2</sup> Hypercholesterolemia: TC ≥5 mmol/L or LDL-C ≥3 mmol/L or the participant was taking lipid-lowering medication. <sup>3</sup> Diabetes: blood glucose level was ≥7.0 mmol/L or diabetes was declared in an interview. <sup>4</sup> Singles: widows/widowers, unmarried, divorced, in separation. <sup>5</sup> Education level: under middle—no education, partial or completed education for primary level, partial secondary education; middle—secondary education, partial academic education; academic—tertiary education; vocational—vocational based on primary or on middle school. <sup>6</sup> Physical activity at leisure (for example, jogging, cycling, swimming, gardening for at least 30 min a day): low level—no such physical activity, once a week or less; middle level—every second or third day; high level—everyday, almost every day; seasonally (e.g., skiing in winter or on the plot in summer).
