Andrew Berardy

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 (PBM), to avoid allergens, pursue a plant-based diet, or reduce their environmental impacts. The base ingredients used in PBM have a wide range of environmental impacts, which may translate to substantial variation across the impacts associated with PBM themselves. To assess the state of the literature on this topic, we performed a scoping review of the environmental impacts of PBM, following the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews. Recent growth in the variety of PBM 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 PBM, but the literature does not examine many other types of PBM. 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 PBM compared to dairy using data from the USDA. PBM 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 PBM available which are presented as environmentally preferable to dairy.

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.

The objective of this study was to use life cycle assessment to estimate the environmental impacts (from farm to factory gate) of the 198 hard-coded line-items included in the food frequency questionnaire of the Adventist Health Study-2 survey and to assess differences among food groups. Life cycle inventories were created using existing data sources and primary data, and their global warming potential (GWP), land use, and water consumption impacts were assessed using the ReCiPe 2016 methodology. In addition to presenting the impacts according to weight and protein content across food groups, we include the novel addition of presenting impacts according to the NOVA classification indicating various levels of processing. Food categories were compared based on one kilogram of edible food, protein food sources were compared based on one kilogram of protein, and NOVA comparisons were based on one serving. In general, meats had the highest environmental impacts per both weight and protein content, while the lowest overall impacts per kilogram came from fruits. Meat analogs had the lowest overall impacts per kilogram of protein, contrary to expectations that additional processing would result in higher environmental impacts when compared to whole plant-based foods. Per serving, ultra-processed foods had the highest GWP, processed foods the highest land use, and minimally processed foods the highest water consumption. Results from this analysis were consistent with other studies. Results from this study suggest that meat and ultra-processed foods have the overall worst environmental impacts, but high water consumption in some minimally processed foods means that those should be carefully considered as well.

JAFSCD: Journal of Agriculture, Food Systems, and Community Development. Publication of the Thomas A. Lyson Center for Civic Agriculture and Food Systems

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.