Adopting more plant-based diets

In this study, two-thirds of women and almost half of men had already changed or were planning to change their diet to more plant-based to combat climate change. According to a recent European consumer survey, half of the participants reported to have reduced their meat intake.⁽¹²⁾ In line with this, also some other studies have shown an increase in vegetarianism or a decrease in meat consumption during the last decades.^{(Reference Lehto, Kaartinen and Sääksjärvi33–Reference Wozniak, Larpin, de Mestral, Guessous, Reny and Stringhini35)}

Women had changed or were planning to change their diet to more plant-based more frequently than men had. Also earlier studies have concluded that women eat less meat and more vegetables, fruit, and other plant-based foods than men^{(Reference Valsta, Tapanainen and Kortetmäki24,Reference Lehto, Kaartinen and Sääksjärvi33,Reference Heuer, Krems and Moon36)} and have less barriers to following more plant-based diets or reducing meat consumption.^{(Reference Pohjolainen, Vinnari and Jokinen14,Reference Tobler, Visschers and green20)} Although some studies show women face more barriers in certain contexts (e.g. pulse consumption),^{(Reference Kuosmanen, Niva and Pajari16)} they are generally more likely to adopt plant-based diets. Eating meat has traditionally been associated with masculinity, power, and wealth,^{(Reference Kildal and Syse37–Reference Marinova and Bogueva39)} which may be one explanation behind sex differences found in most of the studies. In agreement with our findings between higher socio-economic groups and more frequent adoption of more plant-based diets, a direct association between indicators of socio-economic status and plant-based food consumption,^{(Reference Valsta, Tapanainen and Kortetmäki24,Reference Lehto, Kaartinen and Sääksjärvi33,Reference Boylan, Lallukka and Lahelma40)} and an inverse association between socio-economic status and meat consumption^{(Reference Maguire and Monsivais23,Reference Valsta, Tapanainen and Kortetmäki24,Reference Heuer, Krems and Moon36,Reference Pfeiler and Egloff41,Reference Sych, Kaelin and Gerlach42)} have been shown also in previous studies. Other studies have also linked less sustainable attitudes or behaviour to younger age, lower education, lower income, or rural residence.^{(Reference Waldman, Giroux and Blekking25,Reference Sares-Jäske, Valsta and Haario31,Reference Klink, Mata and Frank43,Reference Vainio, Niva and Jallinoja44)} This has been suggested to stem from, for instance, different values, attitudes or traditions, food literacy, lack of information on healthy lifestyle habits, or not perceiving that one would benefit from healthy lifestyle choices.^{(Reference Pampel, Krueger and Denney45,Reference Svendsen, Bak and Sørensen46)} In this study, differences between urban–rural axis categories may be accounted for, for example, by differences in education, traditions, attitudes, or social norms.

Barriers to adopting more plant-based diets

In this study, most women and men reported at least one barrier to change their diet to more plant-based. Generally, barriers to following a plant-based diet have been shown to be common in men, younger age groups, rural residents, those living in households with children, and those with low education.^{(Reference Pohjolainen, Vinnari and Jokinen14)} Furthermore, different kinds of barriers may prevent people from changing their diets. In this study, most common barriers for women and for men were not knowing how to prepare tasty vegetarian food, and doubts about the nutritional value of a plant-based diet.

In agreement with previous findings,^{(Reference Rickerby and Green13)} over one-fifth of the participants in this study felt uncertainty about what food is environmentally friendly or felt that uncertainty about the nutritional value of a plant-based diet prevented them from adopting it. Despite growing awareness of the health benefits of decreasing meat consumption and increasing the consumption of plant-based foods over the last decades, many studies have shown that decreasing meat consumption has not been widely seen as an important climate action.^{(Reference Tobler, Visschers and green20,Reference Marinova and Bogueva39,Reference Hoek, Pearson and James47,Reference Lea and Worsley48)} It seems that animal or plant origin of foods is not perceived as an important environmental factor, and the concept of healthy and environmentally friendly food remains unclear for many. In this study, younger women were more uncertain about environmental friendliness of food, while older participants had more doubts about the nutritional value of plant-based food. Feeling uncertainty is subjective and does not necessarily depend on the actual level of knowledge. Uncertainty about environmentally friendly food was also common in participants with the lowest income, possibly due to socio-economic differences in health literacy.^{(Reference Svendsen, Bak and Sørensen46)}

In addition to lack of knowledge of environmentally friendly foods, also the lack of knowledge on how to prepare tasty vegetarian food, not liking vegetarian foods and the preferences of the close ones were three commonly identified barriers to adopting plant-based diets. In accordance, 30% of the participants of a recent European survey reported that taste was a barrier when choosing plant-based alternatives.⁽¹²⁾ In the present study, not knowing how to prepare tasty vegetarian food was frequently perceived as a barrier in both women and men. The lack of practical knowledge and skills to prepare such food may hinder dietary changes, but also adaptation to unfamiliar flavours and textures may require gradual exposure and time. Not knowing how to prepare tasty vegetarian food was frequent especially in younger women and in women living in households with children. Women with children may perceive that the vegetarian food they make may not meet the preferences of their children or spouses. Indeed, women – and especially women with children – perceived notably more often than men that the preferences of their close ones are a barrier to change their diet to more plant-based, while men reported notably more often than women that not liking vegetarian foods is a barrier for them. It appears that the barriers among women partly derive from preferences of their children and spouses instead of their own preferences.

In this study, affordability was not commonly perceived as a barrier to have a more plant-based diet. In previous studies, however, price and affordability factors have emerged as important drivers behind food selection.^{(12,Reference Mann, Thornton and Crawford19,Reference Waldman, Giroux and Blekking25,Reference Konttinen, Halmesvaara and Fogelholm49)} Despite the affordability not being an important barrier for all population groups in this study, this barrier was more frequent in younger adults, in women living alone, in women with low education, and in women and men with the lowest income compared to the other groups. In agreement, previous studies have emphasised the relevance of socio-economic status in the association between price and affordability and dietary choices.^{(Reference Konttinen, Halmesvaara and Fogelholm49–Reference Green, Cornelsen and Dangour51)} Especially for those with low income, price may pose a serious barrier to choose more sustainable foods.^{(Reference Green, Cornelsen and Dangour51)} However, a recent optimisation study concluded that it is possible to compose a nutritionally adequate and culturally acceptable more plant-based diet while reducing the price of diet,^{(Reference Irz, Sares-Jäske and Tapanainen52)} which implies that with adequate know-how, barriers related to affordability could be diminished.

While approximately 10% of women reported that disinterest in the topic was a barrier to adopt a more plant-based diet, the corresponding share in men was over one quarter. Among men, approximately one-third in the youngest age group, living in remote rural areas, or with the lowest education reported lack of interest. Generally, lack of interest represents a slightly different aspect than other more pragmatic or taste-related barriers. A Dutch study concluded that consumers could be divided into four groups according to their thoughts and actions concerning meat consumption: struggling consumers, coping consumers, indifferent consumers, and strategically ignorant consumers.^{(Reference Onwezen and van der Weele53)} In the present study, those not interested in adopting a more plant-based diet may comprise both indifferent and strategically ignorant consumers. Either way, this group may need different kind of attention in dietary transition than those who perceive more pragmatic or taste-related barriers. Indeed, a Swedish study that explored motivations for active avoidance of carbon emission information stated that those, who are indifferent to the information offered, are not affected by it.^{(Reference Edenbrandt, Lagerkvist and Nordström54)} Thus, providing information on sustainable dietary choices is presumably not effective among those feeling indifference, but other motivators, such as lower prices, convenience or trendiness, could help guide their food choices.

Methodological considerations

The strengths of this study were a nationally representative study sample with a large set of questions related to barriers to adopting plant-based diets and versatile information on sociodemographic factors. This study also includes certain limitations. Firstly, despite a large population survey sample, non-participation bias may have affected the representativeness of the sub-study population. This possible bias was strived to be mitigated by using inverse probability weights that are commonly used in population surveys.^{(Reference Sääksjärvi, Elonheimo and Ikonen28,Reference Härkänen, Karvanen and Tolonen32,Reference Härkänen, Kaikkonen and Virtala55)} Secondly, the term ‘plant-based diets’ was not specified in the survey questionnaire, and the participants may have understood it in various ways. However, as this study examined changes towards more plant-based diets and not any specific plant-based diet, the usage of the wide definition may be less problematic here. Thirdly, the list of barriers to adopting a more plant-based diet was pre-defined in this study and, thus, other potential barriers could not be explored. In future, qualitative studies could investigate the barriers of different groups in more depth. Fourthly, this study used categorised sociodemographic exposure variables in each case instead of continuous variables even though previous literature has indicated that categorisation into, for example, tertiles or quartiles may cause loss of power and inaccurate estimation in epidemiological studies; cause false positive findings as it leads to multiple comparisons; or hinder the comparison between studies as the cut-off points are different.^{(Reference Bennette and Vickers56)} However, in this extensive descriptive study, which aimed to identify sociodemographic groups in which dietary changes and perceived barriers to these changes are more common, categorisation was opted for as an appropriate method to enable similar comparisons of prevalences across all variables. Despite the critique, categorisation of independent variables remains to be a common procedure to treat exposure variables in epidemiological studies. In this study, the possibility of false positive findings was taken into account by using the SMM adjustment for multiple comparisons with row-wise denominator degrees of freedom in pair-wise tests. As our next step in future studies, we aim at examining these associations using continuous exposure variables. Fifthly, social desirability bias may have affected how some of the participants responded to the self-reported questions concerning sustainable dietary changes – possibly leading to slight overestimations of such socially more acceptable behaviours.^{(Reference Callegaro and JL57)} Sixthly, this study was conducted in a cross-sectional setting, which prevented the examination of changes over time. Seventhly, this study was conducted in a Finnish context, and the results may be applicable to some other Nordic or Western countries, yet country or culture specific differences may exist.