A Life Cycle Assessment Approach for Vegetables in Large-, Mid-, and Small-Scale Food Systems in the Midwest US

Adherence to the Mediterranean Food Pattern and Carbon Footprint of Food Intake by Employees of a University Setting in Portugal

BACKGROUND

The Mediterranean diet is characterized by the predominance of the consumption of fruit, vegetables, cereals, nuts, and pulses; consumption of olive oil as the main source of fat; regular but moderate consumption of win; moderate consumption of fish, dairy products, eggs, and white meats; and low consumption of red meat as well as sugar and sugary products. In addition to the reported health benefits, the Mediterranean diet has also been widely recognized as a sustainable food pattern. The objective of this study was to understand the relationship between the degree of adherence to the Mediterranean diet of employees of the University of Porto and the relationship with the carbon footprint of their food consumption.

METHODS

An observational, analytical study was carried out, through the analysis of food consumption data collected in the form of a survey in the previous 24 h inserted in the eAT24 software, as well as the analysis of sociodemographic, lifestyle, and health data collected in the questionnaire. The carbon footprint was calculated from the previous 24 h surveys using data available on a website, obtained in carbon dioxide equivalent per kilogram of food. Sociodemographic, eating habit, and lifestyle questions were selected to understand the relationship between these and adherence to the Mediterranean diet and the carbon footprint of food consumption.

RESULTS

In total, 13.2% of the participants had a Mediterranean diet score equal to or greater than six, and the sample had an average food intake carbon footprint of 8146 ± 3081 CO2eq/Kg of food. A weak, statistically significant positive correlation (r = 0.142, p = 0.006) was observed between Mediterranean diet adherence and the carbon footprint of food intake.

CONCLUSIONS

Most of the participants had a low adherence to the Mediterranean diet, as well as a high carbon footprint of food intake when compared to other countries. People with higher scores for Mediterranean diet adherence have, on average, a higher carbon footprint from food consumption intake.

Environmental and economic sustainability of fresh-cut and pre-cooked vegetables

Due to the growing awareness about the environmental and economic sustainability of food products, the present research aims to evaluate the sustainability of fresh-cut and pre-cooked vegetables, a niche market with growing demand. An analysis was carried out using a detailed material, energy, and economic inventory based on a commercial food processing plant located in northeast Spain. The environmental sustainability was determined using process-based environmental life cycle assessment (E-LCA), applying a cradle-to-market approach, and using the EF3.0 impact assessment methodology to quantify impacts on five midpoint categories (climate change, photochemical ozone formation, acidification, freshwater eutrophication, and fossil resource use) and an aggregated single score. Additionally, an environmental life cycle costing (E-LCC) was performed. The pre-cooked vegetable products showed a higher environmental footprint than the fresh-cut products in all the impact categories (between 14.0 % and 39.9 %) and involved higher life cycle costs (15.2 %), due to the increased demand for ingredients, packaging materials, and electricity consumption per FU (kg of product). The carbon footprint (CF) and the cost for the fresh-cut products were 0.72 kg CO₂ eq/kg and 2.62 €/kg, respectively, compared to 0.86 kg CO₂/kg and 3.02 €/kg for the pre-cooked vegetables. The environmental profiles of both products were rather similar, with a dominance of the Upstream stage (production of ingredients and packaging materials), followed by the Core stage (mainly due to electricity consumed during vegetable processing). The relevance of the Core stage is amplified in the economic analysis due to the incorporation of certain processes which were not included in the process-based E-LCA (e.g., labour, capital, insurance, maintenance costs, etc.). To integrate the economic and environmental analyses, an eco-efficiency index was calculated that describes the carbon emissions per unit of monetary cost, resulting in 0.27 kg CO₂eq/€ for the fresh-cut and 0.28 kg CO₂ eq/€ for the pre-cooked vegetables.

Modeling a localized metropolitan food system in the Midwest USA: Life cycle impacts of scenarios for Des Moines, Iowa

Food systems are energy-intensive, causing ≈25 % of anthropogenic global warming potential (GWP) and contributing to challenges across the food-energy-water nexus. The state of Iowa, USA, is of particular interest as a rainfed agricultural region of the upper Midwest; despite its highly productive landscape, a large proportion of food consumed by Iowa residents is imported. This study focused on the Des Moines Metropolitan Statistical Area (DM-MSA), a six-county area in central Iowa with a 2020 population of ≈700,000. A life cycle assessment approach was used to quantify environmental impacts (GWP, fossil energy and water consumption, land use); scenarios modeled provision and consumption of 50 % of nutritional requirements for the current DM-MSA population by food group (e.g., grains, proteins, vegetables). The four DM-MSA food system scenarios were: 1) current conditions (baseline), 2) local production for 50 % of food, 3) consumption changed to follow USA dietary guidelines, and 4) combined changes to production and consumption. Localizing food production reduced all environmental impacts more than following USA dietary guidelines. Compared to the baseline, 50 % local production scenarios reduced GWP and energy consumption (18-24 %) and water use (35-41 %) annually. Decreases by food group were least for protein (-10 % GWP) and greatest for fruits and vegetables (-58-62 % GWP). Local scenario alternatives could further reduce some environmental impacts if paired with a nutritionally- and environmentally-optimized diet (EAT-Lancet) providing the greatest change (-30-38 % for GWP and energy use) compared to the local scenario. A 50 % local production scenario for the DM-MSA could decrease GWP by 102 million CO_2eq yr^-1 and water use by 44 billion L yr^-1. However, this would require dietary changes based on seasonal food availability. Further development and co-simulation with other metropolitan-scale biophysical and social models will enhance understanding of food system drivers and support effective decision-making for urban food system improvements in the Midwest.

Determination of accurate baseline representation for three Central Iowa watersheds within a HAWQS-based SWAT analyses

Improving food systems to address food insecurity and minimize environmental impacts is still a challenge in the 21st century. Ecohydrological models are a key tool for accurate system representation and impact measurement. We used a multi-phase testing approach to represent baseline hydrologic conditions across three agricultural basins that drain parts of north central and central Iowa, U.S.: the Des Moines River Basin (DMRB), the South Skunk River Basin (SSRB), and the North Skunk River Basin (NSRB). The Soil and Water Assessment Tool (SWAT) ecohydrological model was applied using a framework consisting of the Hydrologic and Water Quality System (HAWQS) online platform, 40 streamflow gauges, the alternative runoff curve number method, additional tile drainage and fertilizer application. In addition, ten SWAT baselines were created to analyze both the HAWQS parameters (baseline 1) and nine alternative baseline configurations (considering the framework). Most of the models achieved acceptable statistical replication of measured (close to the outlet) streamflows, with Nash-Sutcliffe (NS) values ranging up to 0.80 for baseline 9 in the DMRB and SSRB, and 0.78 for baseline 7 in the NSRB. However, water balance and other hydrologic indicators revealed that careful selection of management data and other inputs are essential for obtaining the most accurate representation of baseline conditions for the simulated stream systems. Using cumulative distribution curves as a criterion, baselines 7 to 10 showed the best fit for the SSRB and NSRB, but none of the baselines accurately represented 20% of low flows for the DMRB. Analysis of snowmelt and growing season periods showed that baselines 3 and 4 resulted in poor simulations across all three basins using four common statistical measures (NS, KGE, Pbias, and R²), and that baseline 9 was characterized by the most satisfactory statistical results, followed by baselines 5, 7 and 1.