A Scoping Review of the Environmental Impacts and Nutrient Composition of Plant-Based Milks.

Dairy milk is a ubiquitous nutrient-dense beverage and ingredient, especially in Western diets. However, consumers are increasingly seeking alternatives to dairy, called plant-based milks (PBMs), to avoid allergens, pursue a plant-based diet, or reduce their environmental impacts. The base ingredients used in PBMs have a wide range of environmental impacts, which may translate to substantial variation across the impacts associated with PBMs themselves. To assess the state of the literature on this topic, we performed a scoping review of the environmental impacts of PBMs, following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews. Recent growth in the variety of PBMs available means that there is unlikely yet enough data for conclusive statements regarding environmental impacts of all PBM types, which makes this topic appropriate for a scoping review. We included all relevant documents found through searching scholarly databases. We found 20 studies covering 6 types of PBMs, but the literature does not examine many other types of PBMs. All studies examined use the life cycle assessment methodology. The most data regarding environmental impacts were available for soy- and almond-based milks, and the most common impact quantified was greenhouse gas emissions. We also examined the nutrient composition of PBMs compared with dairy using data from the USDA. PBMs attempt to replicate the organoleptic properties of dairy but often do not exactly match the nutrient profile of dairy. We identified a need for the application of a standardized methodology to facilitate more comprehensive assessment of environmental impacts of the wide variety of PBMs available, which are presented as environmentally preferable to dairy.

Comparison of Plate Waste between Vegetarian and Meat-Containing Meals in a Hospital Setting: Environmental and Nutritional Considerations.

Vegetarian diets can satisfy nutritional requirements and have lower environmental impacts than those containing meat. However, fruits and vegetables are wasted at higher rates than meat. Reducing both food waste (FW) and the environmental impacts associated with food production is an important sustainability goal. Therefore, the aim of this study was to examine potential tradeoffs between vegetarian meals' lower impacts but potentially higher FW compared to meat-containing meals. To examine this, seven consecutive days of plate FW data from Loma Linda University Medical Center (LLUMC) patients were collected and recorded from 471 meals. Mean total FW and associated greenhouse gas emissions (GHGE) were higher among meat-containing meals (293 g/plate, 604 g CO2-eq/plate) than vegetarian meals (259 g/plate, 357 g CO2-eq/plate) by 34 g (p = 0.05) and 240 g CO2-eq (p < 0.001), respectively. Statistically significant differences were observed in both FW and associated GHGE across major food categories, except fruit, when comparing vegetarian and meat-containing meals. Overall, vegetarian meals were preferable to meat-containing meals served at LLUMC both in terms of minimizing FW and lowering environmental impacts. Other institutions serving vegetarian meal options could expect similar advantages, especially in reduced GHGE due to the high CO2 embodied in meat.

A goal-systems perspective on plant-based eating: keys to successful adherence in university students.

OBJECTIVE: To explore adherence to a plant-based diet from the perspective of goals- and motivations-based systems. DESIGN: A cross-sectional, survey-based study was conducted regarding eating patterns, goals and motivations for current eating habits. SETTING: Data were collected using an online survey platform, including the Goal Systems Assessment Battery (GSAB) and other survey tools. PARTICIPANTS: University students were recruited, including thirty-three students reporting successful maintenance of a plant-based diet (Adherents) and sixty-three students trying to adhere to a plant-based diet (Non-adherents). RESULTS: Using GSAB subscale scores, discriminant function analyses significantly differentiated adherents v. non-adherents, accounting for 49·0 % of between-group variance (χ2 (13) = 42·03, P < 0·000). It correctly classified 72·7 % of adherents and 88·9 % of non-adherents. Constructs including value, self-efficacy, planning/stimulus control and positive affect were significant and included in the discriminant function. Logistic regression results suggested that participants who successfully adhered to a plant-based diet were seventeen times more likely to report 'To manage or treat a medical condition' as motivation and almost seven times more likely to report 'To align with my ethical beliefs' as motivation compared with non-adherents. However, these participants were 94 % less likely to report 'To maintain and/or improve my health' as motivation compared with non-adherents. Controlling for motivations, hierarchical logistic regression showed that only planning as part of the GSAB self-regulatory system predicted adherence to a plant-based diet. CONCLUSIONS: Values-based approaches to plant-based diets, including consideration for ethical beliefs, self-efficacy and proper planning, may be key for successful maintenance of this diet long-term.

Intergroup Cooperation in Common Pool Resource Dilemmas.

Fundamental problems of environmental sustainability, including climate change and fisheries management, require collective action on a scale that transcends the political and cultural boundaries of the nation-state. Rational, self-interested neoclassical economic theories of human behavior predict tragedy in the absence of third party enforcement of agreements and practical difficulties that prevent privatization. Evolutionary biology offers a theory of cooperation, but more often than not in a context of discrimination against other groups. That is, in-group boundaries are necessarily defined by those excluded as members of out-groups. However, in some settings human's exhibit behavior that is inconsistent with both rational economic and group driven cooperation of evolutionary biological theory. This paper reports the results of a non-cooperative game-theoretic exercise that models a tragedy of the commons problem in which groups of players may advance their own positions only at the expense of other groups. Students enrolled from multiple universities and assigned to different multi-university identity groups participated in experiments that repeatedly resulted in cooperative outcomes despite intergroup conflicts and expressions of group identity. We offer three possible explanations: (1) students were cooperative because they were in an academic setting; (2) students may have viewed their instructors as the out-group; or (3) the emergence of a small number of influential, ethical leaders is sufficient to ensure cooperation amongst the larger groups. From our data and analysis, we draw out lessons that may help to inform approaches for institutional design and policy negotiations, particularly in climate change management.