A holistic approach for performance evaluation of wastewater treatment plants: integrating grey water footprint and life cycle impact assessment.

Wastewater treatment plants (WWTPs) have positive and negative impacts on the environment. Therefore, life cycle impact assessment (LCIA) can provide a more holistic framework for performance evaluation than the conventional approach. This study added water footprint (WF) to LCIA and defined ϕ index for accounting for the damage ratio of carbon footprint (CF) to WF. The application of these innovations was verified by comparing the performance of 26 WWTPs. These facilities are located in four different climates in Iran, serve between 1,900 and 980,000 people, and have treatment units like activated sludge, aerated lagoon, and stabilization pond. Here, grey water footprint (GWF) calculated the ecological impacts through typical pollutants. Blue water footprint (BWF) included the productive impacts of wastewater reuse, and CF estimated CO2 emissions from WWTPs. Results showed that GWF was the leading factor. ϕ was 4-7.5% and the average WF of WWTPs was 0.6 m3/ca, which reduced 84%, to 0.1 m³/ca, through wastewater reuse. Here, wastewater treatment and reuse in larger WWTPs, particularly with activated sludge had lower cumulative impacts. Since this method takes more items than the conventional approach, it is recommended for integrated evaluation of WWTPs, mainly in areas where the water-energy nexus is a paradigm for sustainable development.

The water footprint of hydrogen production.

Hydrogen (H2) is the most promising energy carrier for reducing the carbon emissions of the energy sector, but the impact of its production on water resources remains unclear. Here, we quantify the water footprint (WF) of different H2 production pathways accounting for the WF of the primary energy used in the production process, as well as feedstock and infrastructure water requirements. Results suggest that green H2 obtained from water electrolysis powered by renewable energy has the lowest WF (65 ± 2 m3/TJ for wind and 204 ± 79 m3/TJ for solar) mostly due to the low WF of renewable energy. The WF of blue H2 derived from fossil fuels is significantly higher (369 ± 30 m3/TJ for natural gas and 564 ± 82 m3/TJ for coal) due to high WF of fossil fuels as well as the water required for carbon capture and storage (CCS). H2 produced from nuclear energy and biomass have extremely high WF (741 ± 277 m3/TJ for nuclear and > 50,000 m3/TJ for biomass). Considering global and country-based energy scenarios, where the main H2 colors (green and blue) individually account for 15 % of energy consumption, we find that the use of green H2 could reduce the water demand of the energy sector while blue H2 would generally increase it, except in countries already characterized by high water consumption due to reliance on water-intensive energy sources. At the global level, we find that for every 5 % of H2 energy adoption, the energy sector could have water savings between 1 and 4 % for green H2 and increase water consumption between 1 and 5 % for blue H2. These results highlight the potential and criticalities of H2 within the water-energy nexus.

Carbon reduction and water saving potentials for growing corrugated boxes for express delivery services in China.

Corrugated packaging for express grew by 90 times to 16.5 Mt y-1 in China, where 81% of recent global express delivery growth occurred. However, the environmental impacts of production, usage, disposal, and recycling of corrugated boxes under the entire supply chain remain unclear. Here, we estimate the magnitudes, drivers, and mitigation potentials of cradle-to-grave life-cycle carbon footprint (CF) and three colors of water footprints (WFs) for corrugated cardboard packaging in China. Over 2007 to 2021, CF, blue and gray WFs per unit package decreased by 45%, 60%, and 84%, respectively, while green WF increased by 23% with growing imports of virgin pulp and China's waste ban. National total CF and WFs were 21 to 102 folded with the scale effects. Only a combination of the supply chain reconstruction, lighter single-piece packaging, and increased recycling rate can possibly reduce the environmental footprints by 24 to 44% by 2035.

Chronotype is associated with Mediterranean dietary adherence and environmental footprints.

This cross-sectional study was carried out to determine the relationship between nutrition according to chronotype and the Mediterranean diet and environmental footprints. "Morningness Eveningness Questionnaire" was used to determine the chronotype classification, and "Mediterranean Diet Adherence Screener" was used to evaluate adherence to the Mediterranean diet. In addition, the food consumption record of the participants was taken and the carbon and water footprints were calculated. A total of 472 adults with a mean age of 22.7 ± 5.0 years participated in the study. Accordingly, 61.0% of the participants were morning type, 15.7% were intermediate type, and 23.3% were evening type. Individuals with higher chronotype values (morning) tended to be more adherent to the Mediterranean diet and had lower environmental (carbon and water) footprints (p < 0.05). The results of this study; showed that diet according to chronotype affects adherence to the Mediterranean diet and environmental footprints.

History and future of water footprint in the Yangtze River Delta of China.

Quantifying the drivers of water footprint evolution in the Yangtze River Delta is vital for the optimization of China's total water consumption. The article aims to decompose and predict the water footprint of the Yangtze River Delta and provide policy recommendations for optimizing water use in the Yangtze River Delta. The paper applies the LMDI method to decompose the water footprint of the Yangtze River Delta and its provinces into five major drivers: water footprint structure, water use intensity, R&D scale, R&D efficiency, and population size. Furthermore, this paper combines scenario analysis and Monte Carlo simulation methods to predict the potential evolution trends of water footprint under the basic, general, and enhanced water conservation scenario, respectively. The results show that (1) the expansion of R&D scale is the main factor promoting the growth of water footprint, the improvement of R&D efficiency, and the reduction of water intensity are the main factors inhibiting the increase of water footprint, and the water footprint structure and population size have less influence on water footprint. (2) The evolution trend of water footprint of each province under three scenarios is different. Compared to the basic scenario, the water footprint decreases more in Shanghai, Zhejiang, and Anhui under the general and enhanced water conservation scenario. The increase in water footprint in Jiangsu under the enhanced scenario is smaller than that of the general water conservation scenario.

Global relevance of Argentinean rainfed crops in a climatic variability context: A water footprint assessment in Buenos Aires province.

Argentina has a relevant international role as a producer of agricultural commodities. Buenos Aires is the province with the largest cultivated area of cereals and oilseeds of the country. Rainfed crops depend exclusively on green water, meaning a comparative advantage for Buenos Aires province. The green virtual water content in the crops produced in Buenos Aires has implications for water allocation at international level. A great amount of countries depends on the Argentinean rainfed agriculture. Therefore, it is important to understand the effects of climate variations on Argentinean crop production at local level and the role of rainfed crops in regional and international trade. We analysed the temporal and territorial variations of crops green water demand in a climatic variability context and their influence on the water footprint. The green water footprint of the main crops of Buenos Aires was assessed, including soybeans, maize, sunflower, wheat and barley, in different climatic conditions: for the period 2008-2018, which include a dry year, a humid year and an ordinary year. A dataset about the green water footprint at municipality level was provided, and the results were presented on maps for each crop and for the different climatic conditions. The relevance of green water of main crops in the world water-dependent supply chains was shown. This comprehensive green water footprint assessment provides a useful database for researchers, companies and policy makers in Argentina and beyond.

Effects of Fish Protein Hydrolysate on the Nutritional, Rheological, Sensorial, and Textural Characteristics of Bread.

The potential enhancement of the protein content in bakery products is studied by adding fish protein hydrolysate (FPH) flour in varying proportions (1.5%, 3%, 4.5%, and 6%) within the production recipe. The mixtures of wheat flour and FPH obtained were comprehensively analysed using Mixolab equipment, evaluating the nutritional, rheological, and enzymatical aspects. The results underscore the substantial potential of FPH as a high-quality protein source evidenced by its polyphenol content and antioxidant value. Moreover, the utilisation of hydrolysed proteins from fish emerges as a viable strategy for reducing the water footprint in food production. Thus, FPH flour showed a protein content of 80.21%, a polyphenol content of 1452 mg GAE/100 g, and an antioxidant activity of 294 mg TE/100 g. While the bread samples made from wheat flour mixed with FPH exhibited a satisfactory rheological behaviour, the presence of an aftertaste and the pronounced fish aroma impacted consumer acceptance. Notably, only the bread sample with 1.5% added FPH met the organoleptic preferences of the consumers, receiving a commendable total acceptability score of 6.2. Additionally, this sample demonstrated favourable results in texture analysis and exhibited an extended shelf life compared to that of the control sample.

Identifying synergistic solutions for the food-energy-water nexus via plastic film mulching cultivation.

Food security, water scarcity, and excessive fossil energy use pose considerable challenges to sustainable agriculture. To understand how rain-fed farming systems on the Loess Plateau, China, reconcile yield increases with ecological conservation, we conducted an integrated evaluation based on the denitrification-decomposition (DNDC) model, agricultural statistics data using the Food-Energy-Water (FEW) nexus indicator. The results showed that maize yields with ridge-furrow plastic film mulching (PFM) were 3479, 8942, and 11,124 kg ha-1 under low (50 kg N ha-1), medium (200 kg N ha-1), and high (350 kg N ha-1) nitrogen (N) fertilizer rates, respectively, and that PFM increased yield and water use efficiency (WUE) by 110-253 % and 166-205 % compared to using no mulching (control, CK), respectively. Plastic film mulching also increased net energy (126-436 %), energy use efficiency (81-578 %), energy productivity (100-670 %), and energy profitability (126-994 %), and nitrogen fertilizer, compound fertilizer, and diesel fuel consumption by agricultural machinery were the main energy inputs. The PFM system reduced water consumption during the maize growing season and the green water footprint and gray water footprint decreased by 66-74 % and 44-68 %, respectively. The FEW nexus indicator, based on a high production at low environmental cost scenario, was greater under the PFM system and had the widest spatial distribution area at the medium-N application rate. Among the environmental factors, the nexus indicator was negatively correlated with precipitation (-0.37), air temperature (-0.36), and the aridity index (-0.36), but positively correlated with elevation (0.17). Our results suggest that the PFM system promotes resource-saving while increasing yields and moves dryland agriculture in an environmentally friendly direction, thus promoting the sustainable development of agroecosystems.

Monitoring grey water footprint and associated environmental controls in agricultural watershed.

The grey water footprint (GWF) is an advanced index linking pollution load and water resources. However, the existing agriculture-related GWF was developed based on hydrological processes, which limits its role in watershed water pollution level (WPL) measurements. The main scope of this study is to calculate GWF and WPL based on runoff, total nitrogen (TN), and total phosphorus (TP) observations in the Hujiashan Watershed of China's Yangtze River Basin. Partial least squares structural equation modeling (PLS-SEM) was utilized to explore the impact pathways of environmental features on GWF and WPL. On this basis, propose measures for the management of this agricultural watershed. The results showed that the TN concentration had a V-shaped trend in 2008-2015, while the TP gradually decreased. The GWF calculations for the TN and TP were compatible with the temporal trends for the concentrations, which were higher in the wet season (0.45 m3/m2 for TN, 0.10 m3/m2 for TP) than in the dry season (0.11 m3/m2 for TN, 0.02 m3/m2 for TP) and increased from upstream to downstream. The WPLs of TN exceeded 2.0 in the midstream and downstream areas, whereas those for TP were inconspicuous. According to PLS-SEM, the GWF is primarily influenced by topographical variables and hydrological features, whereas the WPL is mainly controlled by hydrological features and landscape composition. Fertilizer reduction and efficiency measures should be implemented on farmland and appropriately reducing farming activities on slopes to relieve the GWF and WPL in the watershed.

Water pollution scenarios and response options for China.

China has formulated several policies to alleviate the water pollution load, but few studies have quantitatively analyzed their impacts on future water pollution loads in China. Based on grey water footprint (GWF) assessment and scenario simulation, we analyze the water pollution (including COD, NH3-N, TN and TP) in China from 2021 to 2035 under different scenarios for three areas: consumption-side, production-side and terminal treatment. We find that under the current policy scenario, the GWF of COD, NH3-N, TN, and TP in China could be reduced by 15.0 % to 39.9 %; the most effective measures for GWF reduction are diet structure change (in the consumption-side area), and the wastewater treatment rate and livestock manure utilization improvement (in the terminal treatment area). However, the GWF will still increase in 8 provinces, indicating that the current implemented policy is not universally effective in reducing GWF across all provinces. Under the technical improvement scenario, the GWF of the four pollutants will decrease by 54.9 %-71.1 % via improvements in the current measures related to current policies and new measures in the production-side area and the terminal treatment area; thus, GWF reduction is possible in all 31 provinces. However, some policies face significant challenges in achieving full implementation, and certain policies are only applicable to a subset of provinces. Our detailed analysis of future water pollution scenarios and response options to reduce pollution loads can help to inform the protection of freshwater resources in China and quantitatively assess the effectiveness of policies in other fields.

Carbon trade-off and energy budgeting under conventional and conservation tillage in a rice-wheat double cropping system.

Amid rising energy crises and greenhouse gas (GHG) emissions, designing energy efficient, GHG mitigation and profitable conservation farming strategies are pertinent for global food security. Therefore, we tested a hypothesis that no-till with residue retaining could improve energy productivity (EP) and energy use efficiency (EUE) while mitigating the carbon footprint (CF), water footprint (WF) and GHG emissions in rice-wheat double cropping system. We studied two tillage viz., conventional and conservation, with/without residue retaining, resulting as CT0 (puddled-transplanted rice, conventional wheat -residue), CTR (puddled-transplanted rice, conventional wheat + residue), NT0 (direct seeded rice, zero-till wheat -residue), and NTR (direct seeded rice, zero-till wheat + residue). The overall results showed that the NTR/NT0 had 34% less energy consumption and 1.2-time higher EP as compared to CTR/CT0. In addition, NTR increased 19.8% EUE than that of CT0. The grain yield ranged from 8.7 to 9.3 and 7.8-8.5 Mg ha-1 under CT and NT system, respectively. In NTR, CF and WF were 56.6% and 17.9% lower than that of CT0, respectively. The net GHG emissions were the highest (7261.4 kg CO2 ha-1 yr-1) under CT0 and lowest (4580.9 kg CO2 ha-1 yr-1) under NTR. Notably, the carbon sequestration under NTR could mitigate half of the system's CO2-eq emissions. The study results suggest that NTR could be a viable option to offset carbon emissions and water footprint by promoting soil organic carbon sequestration, and enhancing energy productivity and energy use efficiency in the South Asian Indo-Gangetic Plains.

Unequal prefecture-level water footprints in China: The urban-rural divide.

Water is vital for inclusive human well-being and economic growth, but water and its benefits are not equally distributed to all. The water gap between city dwellers and rural folks was not well understood. In this paper we assessed prefecture-level urban and rural water footprints (WFs) in China, using an improved multi-region input-output (MRIO) table with resolved urban and rural final consumption data. The assessment provided a quantitative foundation for evaluating and explaining urban and rural water use inequality from the consumption perspective. The results showed that per capita urban WF was on average 2.1 times per capita rural WF. The urban-rural WF divide constituted an important contribution to spatial WF inequality, in addition to provincial-level and prefecture-level differences. Compared to previous provincial-level WF analyses, this high-resolution prefecture-level urban and rural analysis showed clear evidence of economically developed urban areas as hotspots of large WFs. Specifically, our results provided a quantitative assessment revealing that 10 % China's population (urban residents in 51 prefectures) appropriated 25.8 % of the national WF. The dominant driving factor for urban-rural per capita WF disparity in all the prefectures was the consumption level, accounting for on average about 84 % of the disparity. There is an urgent need to leverage socio-economic development and urbanization against equitable and sustainable water use. The results have implications to equitable and sustainable water management from a broader macro-economic view.

Comprehensive evaluation of treating drinking water for laying hens using slightly acidic electrolyzed water.

Slightly acidic electrolyzed water (SAEW) is well-known for its highly potent antibacterial properties and safe residue-free nature. In this study, a comprehensive evaluation was conducted on 2 disinfection methods for waterline cleaning in poultry houses: (1) continuously add SAEW into the waterline and (2) the conventional waterline disinfection method, which includes regular use of high-concentration chemical disinfectant for soaking the waterline and flushing with water. The evaluation focused on the effects of these methods on bacteria levels in laying hens' drinking water, the fecal normal rate of laying hens, egg quality, as well as the economic costs and water footprint associated with each method. The results show that the inhibition rate of the control group was 52.45% to 80.36%, which used 1500 mg/L sodium dichloroisocyanurate (DCCNa) for soaking and then flushing with water. The bacterial levels in the waterline returned to pre-treatment levels 26 h after cleaning. However, the experimental group with an available chlorine concentration (ACC) of 0.3 mg/L SAEW showed a higher inhibition rate (99.90%) than the control group (P < 0.05) and exhibited a sustained antimicrobial effect. Regarding eggshell thickness, eggshell strength, and Haugh units of the egg, there were no significant differences between the experimental and control groups. However, the experimental group had higher egg weight and darker yolk color (P < 0.05) than those of the control group. Besides, the experimental group exhibited a higher fecal normal rate and a lower water footprint than those of the control group. Hence, SAEW represents a favorable choice for disinfecting drinking water in poultry houses due to its ease of preparation, lack of residue, energy efficiency, and efficient antibacterial properties. To ensure adequate sanitation, it is recommended to incorporate SAEW with an ACC of 0.3 mg/L into the daily management of the drinking water system for laying hens.

Implementation of the water footprint as a water performance indicator in industrial manufacturing units located in Greece: challenges and prospects.

Global water resources are under great pressure, so sustainable water and wastewater management is essential for every industrial unit. The water footprint (WF) is a multidimensional indicator of volumetric water use and pollution and is applied throughout the production cycle from the supply chain to the end user. The state-of-the art method of calculating the direct (operational) WF requires detailed records of water consumption and wastewater production per process, that are usually not available. In order to effectively implement the indicator, modifications to the standard calculation method are usually necessary, to meet the requirements and characteristics of each production unit. The present study focuses in three production units in Greece (i.e., cement, brewery, and natural cosmetics) and analyzes the modifications and assumptions required for the operational WF assessment, calculated for each production process where possible and for the whole unit. The WF assessment performed for the three case studies showed that both water consumption rates and operational WFs are within the lowest values (4.7 hL water/hL beer for brewery case study and 0.155 L/kg cement for cement case study) of the ranges reported in the international literature (4-8.8 hL water/hL beer and 0.14-0.413 L/kg cement). The total operational WF of the brewery after applying mass balances was calculated at 23.8 hL water/hL beer with virtual grey WF contributing at 79.7% and blue WF at 20.3%. For the cement manufacturing unit, using estimations from the plant operators and data from international literature, the total operational WF of the plant was assessed at 0.159 L/kg cement with blue WF contributing at 95.8%, green WF at 1%, and virtual grey WF at 3.2%. For the natural cosmetics unit, after modifying the system boundaries properly, the total operational WF was assessed at 81.6 L/kg bulk with virtual grey WF contributing at 88.8%. Through WF assessment, strategic actions could be identified to reduce water consumption and a benchmark could be provided to assess water performance between companies of the same branch.

Assessing the effects of drought on rainfed maize water footprints based on remote sensing approaches.

BACKGROUND: Drought affects the characteristics of water use during crop production and so quantitatively evaluating the impacts is important. However, it remains unclear how crop water use responds to drought. To address this gap, water footprint (WF) and standardized precipitation evapotranspiration index (SPEI) were calculated by remote sensing approaches to assess the effects of drought on crop water use. Rainfed maize is the most important crop in Jilin Province, and its growth and water use are more susceptible to drought. The present study explored not only the impact of growing season drought on the maize WF values in Jilin Province, but also the response of WF values to drought at different time scales. RESULTS: Spatially, 72.94% of the WFblue pixels showed a non-significant increase, and the WFgreen in 68% pixels decreased significantly, being mainly concentrated in the middle region. Furthermore, the pixels affected by monthly time scale drought were mainly in the middle region, whereas the pixels affected by annual time scale drought were mainly in the western region. CONCLUSION: Drought not only affected on the source and structure of agricultural water consumption, but also had different effects on WF values at different time scale. These effects had obvious spatial differences. The present study systematically explored the effects of drought on the WF values for rainfed maize in different climate regions and a consideration of these effects could provide valuable information on rainfed maize growth and the agricultural water use response to a changing climate. © 2023 Society of Chemical Industry.

Assessing the potential of GHG emissions for the textile sector: A baseline study.

The carbon footprint (CFP) is a measure of greenhouse gases (GHGs) emitted throughout the lifecycle of a product or activity, while the energy footprint (EFP) and water footprint (WFP) measure energy and water consumption, respectively. These footprints are essential for managing emissions and consumption and promoting low-carbon consumption. A carbon labeling scheme could help consumers make informed choices. Asia is a major textile producer and consumer, so studying textiles' carbon, energy, and water footprints is essential for managing domestic emissions, energy and water consumption, and international trade negotiations. This paper presents a method and framework for assessing CFP, EFP, and WFP at the product level and calculates the footprints for textile products. The results show that the total CFP of all textile products produced is 42,624.12 MT CO2e, with indirect emissions contributing significantly more than direct emissions. The total EFP is 248.38 PJ, with electricity consumption being the main contributor, while the total WFP is 80.71 billion liters. The spinning stage of production has the highest CFP and EFP, and energy consumption is the main contributor to all footprints. These results can help compare different products and reduce the footprints of the textile sector.

Optimization of virtual water flows in agriculture by changing cropping patterns using an integrated approach.

Utilizing available water resources efficiently is crucial to address both our present and future requirements and plays a vital role in safeguarding food security. This current investigation deals with assessment and optimizing water footprint (WF) and virtual water flow (VWF) for primary crops in Banas River Basin (BRB) using AquaCrop model with local datasets and district-level estimates. VWF in the basins were estimated by multiplying the WF of crops with the amount exported/imported, which is determined based on the difference between production and consumption in the basin. The possibility of changing the cropping patterns was evaluated for the potential reduction of the blue WF. Annual WF from primary crops in the basin amounts to 19,255 MCM/yr (70 % green, 21 % blue and 10 % grey WF, respectively). Banas basin is a net exporter of agriculture commodities with nearly 7391 MCM/yr of water flowing out of the basin due to agricultural exports of which approximately 265 MCM/yr is virtual blue water outflow. Crops having low economic water productivity of blue water are being grown in vast areas resulting in a high blue WF. The optimizing the cropping pattern can result in a 5-42 % lower blue water footprint with 11-39 % higher economic output under different scenarios with and without considering the consumption needs. Changing the cropping pattern and making trade plan to optimize the crop import/exports can be viable option for tackling the blue water scarcity issues in the basin. WF can be managed sustainably by improving water resource allocation for better economic, social, and environmental productivity and going for less aggressive agricultural production.

Case Study on the Impact of Water Resources in Beef Production: Corn vs. Triticale Silage in the Diet of Limousine × Podolian Young Bulls.

In this study, we have included the water footprint (WF) in the process of optimizing animal feed rations. The global footprint of cattle production accounts for the largest share (33%) of the global water footprint of livestock production. Using two homogeneous groups of Limousine × Podolian young bulls, two different diets were compared: corn silage feeding (CSF), with a corn silage-based diet; and triticale silage feeding (TSF), with a triticale silage-based diet. Silage constituted about 41% and 46% of the feed composition (for CSF and TSF, respectively). Diets were characterised by the same energy and protein content. Despite the lower WF in the TSF group than in the CSF group (7726 vs. 8571 L/day/calf respectively), no significant differences were found in animal performances (i.e., daily weight gain and final weight), feed conversion or income over feed costs. These results show that simple production decisions can have a significant impact on water resource. Therefore, the use of triticale silage should be further promoted, especially in world regions with limited water resources where low WF feed formulation is more strategic than elsewhere.

Effects of isoenergetic supplementation as water use mitigation strategy on water footprint and health of nursing bull calves.

Sustainable livestock systems focus on mitigating natural resource use such as water. Dietary management strategies can significantly reduce the water footprint of livestock animals; however, animal health is of concern when animals reduce water intake due to subacute dehydration. To evaluate potential consequences of this nutritional management intervention, a total of 23, 60 ±â€…3 days old nursing Holstein bull calves, weighing 94.7 ±â€…12.07 kg, were distributed in a completely randomized design and received one of three diets. Control was a basal diet composed of a non-medicated milk replacer (milk replacer; n = 7), and the additional two diets, were composed of the same non-medicated milk replacer in addition to either lipid [n = 8; milk replacer + menhaden fish oil (3 %)] or soluble carbohydrate [n = 8; milk replacer + corn starch (7%) isoenergetic to fat group] supplements. Animals were offered ad libitum mineral mix and water, as well as 120 g/day of a composite mix of dried microbrewery's spent grains. Data were analyzed as linear and generalized linear mixed models with diet as a fixed effect and animal as random utilizing R studio (R Core Team, 2021, Vienna, Austria; SAS Inst., Cary, NC). Within supplementation groups, lipid supplemented calves had the highest lymphocyte (63.24 vs 57.69 counts/100 lymphocytes; P < 0.033), and lowest neutrophil counts (29.3 vs 35.3 counts/100 lymphocytes; P < 0.047). Supplementation significantly increased total serum protein (P = 0.001) and skin moisture (P < 0.011), with carbohydrate group having the highest skin moisture (5.30 vs 3.99; P < 0.047). Supplementation also decreased fecal fluidity scores (P < 0.001) with no significant change in serum electrolytes (P > 0.256). No significant differences were found amongst treatments for the ingestive behavior (P > 0.338). The carbohydrate-supplemented calves significantly decreased all daily water footprints compared to the control and fat-supplemented groups: blue a 47.55 L decrease, (P < 0.001), green a 265.62 L decrease (P = 0.005), and gray a 55.87 L decrease (P = 0.009) water footprint, as well as total water footprint (369.04 L, P = 0.004). Our results indicate the potential to maintain animal performance while increasing water use efficiency through diet supplementation tailored to mitigate water use, without adverse effects on animal health.

Commercial weight-loss diets, greenhouse gas emissions and freshwater consumption.

BACKGROUND: Weight-loss attempts are widespread in the United States, with many using commercial weight-loss diet plans for guidance and support. Accordingly, dietary suggestions within these plans influence the nation's food-related environmental footprint. METHODS: We modelled United States (US) per capita greenhouse gas emissions (GHGe) and water footprints associated with seven commercial weight-loss diets, the US baseline, and selected other dietary patterns. We characterised consumption in commercial weight-loss diets both via modelling from provided guidelines and based on specific foods in 1-week meal plans. Cradle-to-farmgate GHGe and water footprints were assessed using a previously developed model. GHGe results were compared to the EAT-Lancet 2050 target. Water footprints were compared to the US baseline. RESULTS: Weight-loss diets had GHGe footprints on average 4.4 times the EAT-Lancet target recommended for planetary health (range: 2.4-8.5 times). Bovine meat was by far the largest contributor of GHGe in most diets that included it. Three commercial diets had water footprints above the US baseline. Low caloric intake in some diets compensated for the relative increases in GHGe- and water-intensive foods. CONCLUSIONS: Dietary patterns suggested by marketing materials and guidelines from commercial weight-loss diets can have high GHGe and water footprints, particularly if caloric limits are exceeded. Commercial diet plan guidance can be altered to support planetary and individual health, including describing what dietary patterns can jointly support environmental sustainability and weight loss.