In recent years, the adoption of a strict plant-based (vegan) diet (PBD) that is appropriately planned and supervised has become an increasing interest. New national data in Slovenia report that 1% of older adults, 3.3% of adults, and 3.1% of adolescents currently practice vegetarian diets, while only 0.4% of adolescents and adults reported practicing a strict PBD [
From prospective cohort studies, it was found that PB dieters had healthier lifestyle habits than nonvegetarians [
Adopting a strict PBD is demanding, with many individuals regularly facing problems and obstacles. The transition to a strict PBD may be more successful when participants are involved in a lifestyle-optimizing program providing a rationale for the diet change through lectures, prescribed meal plans, counseling, and social support [
To become long-term, motivated, and healthy plant-based dieters, individuals need to change their lifestyle behaviors. A healthy and active lifestyle is associated with health and quality of life [
We developed a whole-food, plant-based (WFPB) lifestyle program (described in the Methods section) based on a WFPB diet and reported its effects on body composition and cardiovascular (CV) risk factors over 10–36 weeks [
We included participants from different parts of Slovenia who voluntarily joined our ongoing, community-based, WFPB lifestyle program (see description below) 0.5–10 years ago. The study protocol was approved by the National Medical Ethics Committee (No. 0120-380/2019/17) and the Ethical Committee in the field of sports (No. 05:2019). The trial was registered at
We described subject selection in detail in our previous study which is a part of the same larger study (see text and Figure 1 on pages 3 and 4 of [
In this primary prevention setting, we excluded current pregnancy or lactation, current competitive or top-level athletes, major musculoskeletal restrictions, active malignant diseases (e.g., cancer, cardiovascular diseases (CVD), type 2 diabetes, autoimmune diseases, and neurodegenerative diseases), the current use of drugs for measured blood markers (e.g., plasma lipids, blood pressure, blood sugar control), >3% of energy intake from animal protein, incomplete blood assay, and unanswered questionnaires. A total of 370 participants met the inclusion criteria; 204 declined to participate.
In the final analysis, we included 151 adult participants (91% of those initially included), who were all from the same ethnic group (Caucasian race). Based on the duration of their voluntary participation in our WFPB lifestyle program, we divided participants into 3 groups: short-term (0.5–<2 years), medium-term (2–<5 years), and long-term (5–10 years).
The diet consisted of ≥90% of energy intake from WFPB diet and ≤10% of energy intake from plant-based meal replacement (MR) (35–37 g plant protein (soy or pea)/100 g; 1-2 portions/day) and dietary supplements (e.g., vitamin B12 for all participants, vitamin D3 in winter months, optional eicosapentaenoic acid, and docosahexaenoic acid (i.e., omega-3 long-chain polyunsaturated fatty acids). The WFPB diet was based predominately on whole or minimally processed plant foods as defined by Campbell and Campbell in 2005 [
It was divided into habitual, organized, and nonorganized PA. During the introduction phase, participants engaged in at least two 45-minute, guided, moderate-intensity exercise sessions weekly. After the introduction phase, participants performed the prescribed resistance workout activities by themselves. They were also encouraged to perform ≥30 minutes/day of low–moderate-intensity aerobic activity and a longer low–moderate-intensity activity during the weekend (>45 minutes, preferably 60–120 minutes), like brisk walking or hiking.
It consisted of regular follow-ups and body composition measurements, meal plan evaluations, grocery tours, cooking workshops, assistance in the introduction of PA, individual and group support, and social media support, including (1) cooking recipes, (2) professional summaries of health and nutrition topics written in lay language, (3) posting organized group workouts and results/testimonials, and (4) a discussion board. The goal was to motivate and teach participants to improve their diet, lifestyle (i.e., quit smoking and increase PA), and consequently their well-being and health.
We adopted the questionnaire provided by the National Institute of Public Health [
Participants were measured without shoes, socks, outer clothing, mobile devices, and/or keys in pockets by the same two researchers. Height (cm) was measured using the body height gauge (Kern MPE 250K100HM, Kern and Sohn, Balingen, Germany). Body composition was assessed using an 8-electrode, medically approved, calibrated, bioelectrical impedance body composition monitor (Tanita 780 S MA, Tanita Corporation, Tokyo, Japan), which provided an accurate tool to measure total BF% and fat-free mass in healthy young males and females, regardless of their level of habitual PA [
To assess PA, inactivity, and time spent using passive transport during the previous 7 days, we used the self-administered Long International Physical Activity Questionnaire (L-IPAQ) [
The volume of activity was computed by weighting each type of activity by its energy requirements defined in metabolic equivalent of task (METs), where 1 MET is the resting metabolic rate obtained during quiet sitting, equivalent to the energy consumption of 1 kcal/kg/hour) [
Vigorous-intensity PA is defined as achieving a minimum total PA of at least 1500 MET minutes/week, at least three days per week, or seven days per week of any combination of walking-equivalent, moderate-intensity PA, or vigorous-intensity PA to achieve a minimum total PA of at least 3000 MET minutes/week [
We used 19 self-rated questions from the Pittsburgh Sleep Quality Index (PSQI) questionnaire [
To measure stress status during the previous month, we used a 30-question Perceived Stress Questionnaire (PSQ) [
We asked participants to rank 8 different motives, where 1 was the least important and 8 was the most important: (1) health, (2) BM management/appearance, (3) environmental concerns, (4) religious reasons, (5) affordable dieting, (6) convenient dieting, (7) animal ethics, and (8) satiety/no hunger. For each motive, we calculated the average scores from the whole sample or from individual groups according to the time spent in our program.
Statistical analysis was performed using R 3.5.2 with the dplyr [
We included 151 adults from six regions of Slovenia and allocated them to three groups according to the duration in our WFPB lifestyle program: (1) short-term (0.5–<2 years), (2) medium-term (2–<5 years), and (3) long-term (5–10 years). The average duration spent in the WFPB lifestyle program for all participants was 4.1 years: 1.3 years for group 1, 3.9 years for group 2, and 7 years for group 3. Group 1 included 51 participants (35 females (69%) and 16 males (31%)), group 2 included 56 participants (43 females (77%) and 13 males (23%)), and group 3 included 44 participants (31 females (70%) and 13 males (30%) (
All participants were previously engaged in a Western-type diet and lifestyle, which we assessed from a questionnaire. Most lived in a marriage or partnership status (74.9%), lived outside the Capitol (62.3%), were employed or self-employed (79.4%), and had at least mildly above-average economic status (94.7%). The majority were primary, high-school, and college-educated (48.4%). Only 2% (3) of the participants consumed alcohol (<0.5 g alcohol/day, calculated from the three-day weighted dietary protocol [
There were no significant differences between short-, medium-, and long-term WFPB lifestyle program participants in demographics and other characteristics, except for BF%, employment, and income status. Group 3, the long-term group, had the lowest average BF%, more self-employed participants, fewer high-school or college-educated participants, and fewer middle financial class (income from 701 to 1900 euros/month) participants (Table
The mean BMI values of groups 1, 2, and 3 were 24.3 (SD: 4.0) kg/m2, 24.4 (SD: 4.0), and 22.9 (SD: 3.0) kg/m2 (
BMI and BF% obesity classification of all participants by gender and according to their length of engagement time in our program.
Whole sample | Group 1 | Group 2 | Group 3 | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Gender ( | Female (109) | Male (42) | F/M | |||||||||
% | % | % | % | % | 0.087 | |||||||
Underweight (BMI <18.5) | 2 | 1.8 | 0 | 0 | 0 | 0 | 2 | 3.6 | 0 | 0 | ||
Normal weight (BMI 18.5–24.9) | 81 | 74.3 | 23 | 54.8 | 38 | 74.5 | 31 | 55.4 | 35 | 79.5 | ||
Preobesity (BMI 25–29.9) | 20 | 1.8 | 16 | 38.1 | 9 | 17.6 | 19 | 33.9 | 8 | 18.2 | ||
Obesity class 1 (BMI 30–34.9) | 4 | 3.7 | 2 | 4.8 | 2 | 3.9 | 3 | 5.4 | 1 | 2.3 | ||
Obesity class 2 (BMI 35–39.9) | 2 | 1.8 | 0 | 0 | 2 | 3.9 | 0 | 0 | 0 | 0 | ||
Obesity class 3 (BMI >40) | 0 | 0 | 1 | 2.4 | 0 | 0 | 1 | 1.8 | 0 | 0 | ||
>35% | >25% | 0.739 | 0.446 | |||||||||
No | 101 | 92.7 | 38 | 90.5 | 45 | 88.2 | 52 | 92.9 | 42 | 95.5 | ||
Yes | 8 | 7.3 | 4 | 9.5 | 6 | 11.8 | 4 | 7.1 | 2 | 4.5 |
Statistically significant values are written in bold. Fisher’s exact test was used for group comparison.
In terms of BF%, 88.2%, 92.9%, and 95.5% of participants in groups 1, 2, and 3 were in the normal range, respectively [
Everyday Sitting, Transport Time, and PA. Participants (151) reported moderate transport time (41.7 (SD: 33.4) minutes/day), relatively low weekly and weekend prolonged daily sitting (averages of 4.0 and 5.0 hours, respectively), and high amounts of PA (1488.3, 2171.4, and 1901.9 average MET minutes/week of walking-equivalent, moderate-intensity, and vigorous-intensity PA), with a total PA level of 5541.2 MET minutes/week. There were no significant differences in everyday sitting, transport time, and PA status observed between the groups (Table
PA of all participants and according to their length of engagement time in our program.
L-IPAQ score | Whole sample | Group 1 | Group 2 | Group 3 | |||||
---|---|---|---|---|---|---|---|---|---|
Mean | SD | Mean | SD | Mean | SD | Mean | SD | ||
(1) Transportation | 41.7 | 33.4 | 43.6 | 37.2 | 43.0 | 37.2 | 37.9 | 31.4 | 0.671 |
(2) Weekly sitting (h/day) | 4.7 | 2.9 | 4.3 | 2.8 | 5.3 | 3.2 | 4.6 | 2.5 | 0.189 |
(3) Weekend sitting (h/day) | 4.0 | 2.3 | 3.8 | 2.2 | 4.1 | 2.5 | 4.1 | 2.3 | 0.804 |
(4) Walking PA (MET min/week) | 1488.3 | 1811.4 | 1300.5 | 1261.2 | 1544.2 | 2234.1 | 1634.9 | 1773.1 | 0.644 |
(5) Moderate-intensity PA (MET min/week) | 2171.4 | 2365.0 | 1906.2 | 1712.5 | 1972.5 | 2282.6 | 2731.7 | 2996.9 | 0.174 |
(6) Vigorous-intensity PA (MET min/week) | 1901.9 | 2819.6 | 2439.6 | 4062.7 | 1447.5 | 1839.4 | 1856.9 | 1892.1 | 0.191 |
(7) Total (MET min/week) score | 5541.2 | 4677.0 | 5612.5 | 5181.2 | 4943.8 | 4294.4 | 6218.9 | 4534.5 | 0.399 |
Resistance workout | 2.7 | 0.9 | 2.8 | 0.9 | 2.5 | 0.8 | 2.8 | 1.0 | 0.084 |
ANOVA was used for group comparison.
A total of 16.6% (25) of participants sat for more than 8 hours/day during the week, while 9.3% (14) of participants sat for more than 8 hours/day during the weekend. In terms of exercise, 87.4% (132) of participants exceeded the recommendations for the minimum amount of moderate-intensity PA (≥500 MET minutes/week) [
All participants had good sleep quality and patterns on average (Table
The participants' total score (average PSQ = 0.29 (SD: 0.1)) indicated low average stress levels. Furthermore, 20.5% (31) of participants experienced moderate stress status (PSQ score: 0.34–0.46), while 13.2% (20) of participants experienced severe stress status (PSQ score: >0.46). No significant differences were observed in the group comparison (Table
Perceived stress of all participants and according to their length of engagement time in our WFPB program.
Motive scores according to the time spent in the WFPB lifestyle program are presented in Figure
Motives for adopting PBD. (a) Group 1. (b) Group 2. (c) Group 3.
We discovered no significant differences in lifestyle between the participants in our WFPB lifestyle program, regardless of the length of time they had spent in the program, potentially due to an extensive support system provided. Our results showed that it was possible to maintain a favorable balance between compliance to a supplemented WFPB diet, PA, and a healthy lifestyle. Participants implemented the proposed lifestyle changes as suggested and exhibited, on average, normal BMI and BF% values [
Only 2.0% (3) of the participants consumed alcohol (mean: <0.5 g/day) versus 70.0% of adults in the general population in Slovenia (1 g/day) [
Long-term beneficial lifestyle change for behavioral benefits and obesity management require an ongoing long-term intervention and support system [
On average, our participants’ BMIs were within the normal BMI range
Comparing our results with World Health Organization (WHO’s) BMI [
According to the BMI classification, 29.8% of our participants aged 18–78 years were overweight or obese. According to the BF% classification, only 7.9% of participants were overweight or obese. In contrast, 59% of the adult Slovenian population were overweight or obese according to BMI classifications [
Comparison of the participants according to the length of time in the WFPB lifestyle program (i.e., short- (0.5 ≤ 2 years), medium- (2 ≤ 5 years), or long-term (5 ≤ 10 years)) showed no significant differences in terms of BMI and %BF. However, our results are based on a cross-sectional study, while our previous nonrandomized study showed further improvement of weight loss at 9 months (i.e., 36 weeks) compared to 2.5 months (i.e., 10 weeks) [
Our study confirms that participants implemented a healthy lifestyle relatively quickly (i.e., already 0.5 ≤ 2 years in the program) and were able to maintain it medium- and long-term (i.e., at 2 ≤ 10 years). Centenarian and longest-lived-population studies associated a low incidence and mortality of cancer and CVD with exclusive or predominant PBD [
In our study, we used a self-administered L-IPAQ questionnaire with acceptable reliability and validity when assessing the levels and patterns of PA in healthy adults in diverse settings [
Our results showed similar trends to the results of the Slovenian National Institute of Public Health, where sitting time was divided based on the type of work. The average weekly sitting time in our study (five and four hours/day during the week and weekend) was the same as that found for the general adult Slovenian population. In our study, 16.6% (25) and 9.3% (14) of participants sat during the week and weekend for over 8 hours/day, while the Slovenian population study reported that for simple office work and for intellectual, research, and management-type work, the average daily sitting times were 8.2 and 7.5 hours/day [
According to the study on the burden of diseases in 187 countries, a low level of PA was the 10th leading risk factor for morbidity [
Our participants reported moderately motorized (mostly cars) transport time, with an average of 42 minutes/day spent traveling, while 19.2% of participants reported using motorized transport <10 minutes/day.
On average, our participants exercised 5541.2 MET minutes/week. Participants in our study incorporated PA more as an integrated lifestyle component and in combination with a diet where the commitment was maintained through the assistance of an extensive support system and community network. A total of 90.7% of participants performed at least the minimum amount of weekly recommended moderate-intensity PA [
We found that the average time to go to sleep was mostly late, at 22:46, while the average waking time was 5:54 am. Participants reported falling asleep in less than 15 minutes, with the average sleep duration being fewer than seven hours per night. However, 24.5% (37) of participants reported fewer than six hours of sleep per day. In comparison, a study on the Slovenian population reported only 12.5% of adults sleeping for fewer than six hours a day [
On average, participants in our study reported low perceived stress levels, with no significant differences observed between the three groups
Most participants (66.2%) experienced low stress, 20.5% experienced moderate stress, and 13.2% of participants reported a severe stress status. Compared to the results from the Slovenian National Institute of Public Health, our results might show a favorable stress status, particularly regarding the moderate and severe stress statuses. In comparison, bearing in mind the limitations surrounding the different methodologies, about one-quarter (23.2%) of the adult Slovenian population experienced stress daily, while 22.6% experienced severe stress challenges [
Stress exposure increases the risk of poor clinical outcomes across a variety of major health conditions [
For 93% of the participants, health was the primary motive for primarily engaging in a PBD, while the least important motive was for religious reasons. Interestingly, group 3, which was the group in which participants had spent the longest amount of time on the PBD compared to groups 1 and 2, showed a nonsignificant trend toward increased motives for environmental and animal ethics reasons. These results were probably more coincidental or, according to anecdotal conversations with participants, might be based on a higher level of consciousness after achieving health or BM management goals.
According to previous studies, common motives for choosing a strict PBD (vegan) included ethical and health-related benefits, BM management, environmental concerns, and religious reasons [
The strengths of our study include its long-term nature, since the participants were healthy and active adults who voluntarily joined our WFPB lifestyle program 0.5–10 years ago, thereby resulting in their transformation from a Western-type, sedentary lifestyle to an active, WFPB lifestyle program. A unique feature of this study in accordance with the program is the ability to obtain detailed descriptions of their lifestyles and accompanying an extensive support system. The study also had good geographical representation, since our participants were dispersed across the country in several regions of Slovenia, including urban, suburban, and rural areas. All lifestyle measurements from the fairly large sample were performed within 14 days. Furthermore, this study was a part of an extensive project where we also investigated in detail dietary intake from foods and supplements according to nutrients and compared these data with the recommendations according to food groups. We also investigated the associations between nutrition and CV health status and some other blood markers [
Our study has some obvious limitations inherent to epidemiological studies due to the possibility of under- or overreported estimates of lifestyle components assessed by questionnaires. As a limitation, there is a constant need for larger cross-sectional samples (especially males) and nonrandomized studies. In addition, we could not exclude the possible unknown impact of people within the set criteria who did not respond or were not willing to participate in the study. Additional stimuli to improve the success of the WFPB lifestyle change included the enhanced and extensive support system [
This research was one of the first studies to systematically assess the lifestyle factors and motives in the adoption of a PBD according to the length of time that participants had spent in a community-based WFPB lifestyle program. All participants were involved in the program for 0.5–10 years and were previously on Western-type diets. On average, participants exhibited normal BMI and BF% values, were physically very active, had good sleep quality, and had low levels of perceived stress. The main motive for the WFPB dietary pattern was the expected health benefits. There were no significant differences in lifestyle status between the participants in our WFPB lifestyle program regardless of the length of time spent in the program, potentially due to the extensive support system provided.
The data used to support the findings of this study are included within the article.
All authors declare no conflicts of interest. B. J. and S. P. are receiving royalty compensation at Herbalife Nutrition.
The authors wish to thank all health coaches for their collaboration. The authors would like to thank Uroš Godnov (Faculty of Management, University of Primorska) for his assistance with the statistical analysis and Alenka Polajnar Gantar for the language review. Last but not least, the authors would like to show our gratitude to all participants in the study; this work would not have been possible without them. The work was partly financially supported by the Slovenian Research Agency (Research Program P3-0395: Nutrition and Public Health) and partly by the resource of Barbara Jakše, sole proprietor.
Table 1S: demographic and other characteristics of the study participants. Table 2S: sleep quality and patterns of all participants according to their length of engagement time in our program. Table 3S: perceived stress of all participants and according to their length of engagement time in our WFPB program. Table 4S: motives for adopting PBD.