Assessing the environmental impact of diets.

Proposing a Novel Index Reflecting Both Climate Impact and Nutritional Impact of Food Products

Region-specific nutritious, environmentally friendly, and affordable diets in India

Better information on greenhouse gas (GHG) emissions and mitigation potential in the agricultural sector is necessary to manage these emissions and identify responses that are consistent with the food security and economic development priorities of countries. Critical activity data (what crops or livestock are managed in what way) are poor or lacking for many agricultural systems, especially in developing countries. In addition, the currently available methods for quantifying emissions and mitigation are often too expensive or complex or not sufficiently user friendly for widespread use.The purpose of this focus issue is to capture the state of the art in quantifying greenhouse gases from agricultural systems, with the goal of better understanding our current capabilities and near-term potential for improvement, with particular attention to quantification issues relevant to smallholders in developing countries. This work is timely in light of international discussions and negotiations around how agriculture should be included in efforts to reduce and adapt to climate change impacts, and considering that significant climate financing to developing countries in post-2012 agreements may be linked to their increased ability to identify and report GHG emissions (Murphy et al 2010, CCAFS 2011, FAO 2011).

Water, land and carbon footprints of sheep and chicken meat produced in Tunisia under different farming systems

The aim of this paper is to identify a set of crucial indicators to assess the most pressing environmental impacts of diets. Based on a literature review, 55 potential assessment methods were selected and their distinctive indicators identified. The methods were classified according to their position in the DPSIR framework [chain of Drivers, Pressures, State (changes), Impacts, and Responses], and into 15 environmental issues at three levels. The selection was narrowed down to eight, based on the availability of reliable methods, their relevance to agri-food systems, their frequent application for diets, and their recommendation by international bodies. (1) At the global (supra) level, the planetary boundaries approach addresses the current global environmental (change in) state and helps to prioritize the most pressing issues related to the agri-food system as a driver. These issues are climate change, nitrogen and phosphorus cycle disruption, land-use change, and freshwater use. (2) At the national (macro) level, the footprints approach is used to identify indicators. This footprint family includes ecological, land, carbon, energy, and water footprints. International bodies support these key indicators, but they recommend complementary assessment methods for nitrogen and phosphorus flows, soil health, and pesticide use. (3) At the product (micro) level, life cycle assessment includes 11 pressure indicators. Of the latter, greenhouse gas emissions (GHGEs) and land use (LU) are the most frequently used indicators in diet studies. We conclude that GHGEs and LU fulfill the selection criteria and address most of the environmental impact of diets well. In the future, these indicators should be supplemented with an indicator addressing the nitrogen and phosphorous efficiency of food products.

Land, carbon and water footprints in Taiwan

Greenhouse gas (GHG) emissions from unsustainable land-use practices around the world contribute significantly to anthropogenic climate change. Growing population pressure and low efficiency of agricultural production systems in Sub-Saharan Africa (SSA) trigger the expansion of agricultural land into natural ecosystems, which leads to deforestation and land degradation, and causes GHG emissions. At the same time, prolonged droughts and increasingly erratic weather patterns due to climate change jeopardise food security in SSA countries such as Kenya.

The food chain contributes to a substantial part of greenhouse gas (GHG) emissions and growing evidence points to the urgent need to reduce GHGs emissions worldwide. Among suggestions were proposals to alter food consumption patterns by replacing animal foods with more plant-based foods. However, the nutritional dimensions of changing consumption patterns to lower GHG emissions still remains relatively unexplored. This study is the first to estimate the composite nutrient density, expressed as percentage of Nordic Nutrition Recommendations (NNR) for 21 essential nutrients, in relation to cost in GHG emissions of the production from a life cycle perspective, expressed in grams of CO2-equivalents, using an index called the Nutrient Density to Climate Impact (NDCI) index. The NDCI index was calculated for milk, soft drink, orange juice, beer, wine, bottled carbonated water, soy drink, and oat drink. Due to low-nutrient density, the NDCI index was 0 for carbonated water, soft drink, and beer and below 0.1 for red wine and oat drink. The NDCI index was similar for orange juice (0.28) and soy drink (0.25). Due to a very high-nutrient density, the NDCI index for milk was substantially higher (0.54) than for the other beverages. Future discussion on how changes in food consumption patterns might help avert climate change need to take both GHG emission and nutrient density of foods and beverages into account.

Background: Food production is a major driver of environmental change, while dietary risks are the leading cause of global disease burden. Studies suggest that adoption of healthy diets in high-income countries can provide environmental co-benefits. However, little is known about such options in low and middle-income countries. India is home to one-fifth of the global population, and experiencing complex nutritional challenges, alongside critical environmental pressures on its ability to produce food. This project assesses the potential for dietary change to improve health and diet-related environmental footprints in India. Methods and results: A systematic review assessed the sustainable dietary patterns studied in the literature, and their impacts on a range of environmental indicators, to understand which diets may lead to improved environmental and health outcomes. Adoption of sustainable diets is generally estimated to reduce environmental footprints, though large variations in reductions are seen across sustainable diet types. Following national dietary guidelines may be a relevant public health goal with both environmental and health benefits. A comparison was undertaken of a number of dietary intake data sources in India, examining relative differences in overall intake, and intake of key food groups, to better understand data suitability for sustainable diet analyses. The comparison highlighted the 2011-2012 National Sample Survey (NSS) household expenditure surveys as a relevant data source for the project, though data sources showed high variability in intake, particularly for a set of key nutrient-dense food groups. The NSS and environmental footprint data were matched to estimate the change in greenhouse gas (GHG) emissions, land use (LU), and water footprints (WFs) that may result from national adoption of healthy dietary guidelines, and contrasted this with a scenario of widespread uptake of “affluent” diets. A shift to healthy guidelines in India would result in a small increase in environmental footprints (4-5% for GHG emissions, LU and WFs), though this national result masked large variations among sub-samples; for example, healthy diet shifts among those who consume above recommended dietary energy could decrease emissions by 6-16% across the three environmental indicators. Shifts to affluent diets would result in large increases of about 19-36% across indicators. Lastly, differences in cost were assessed between observed healthy and lowerfootprint diets, and average diets with sufficient dietary energy (“adequate” diets). Overall, healthy diets with lower footprints were slightly more expensive than an adequate diet. Large variations were observed among sub-samples of the population: improved diets were particularly more expensive for lower-income individuals and rural residents, while cheaper, or had no difference in price, for individuals in the highest quartile of socioeconomic status, and for urban residents. Higher expenditure on improved diets was particularly associated with fruit and vegetables, and dairy. Conclusions: Achieving the critical public health goal of healthy diets while minimising diet-related environmental footprints in India may require three broad strategies: increasing the efficiency of agricultural production, alongside efforts to improve the affordability of healthy dietary change, and the active promotion of healthy and lower-footprint diets for those who can currently afford them.

Diets benefiting health and climate relate to longevity in northern Sweden

Soil organic carbon (SOC), greenhouse gas (GHG) emissions and water footprint (WF) are the key indicators of environmental sustainability in agricultural systems. Increasing SOC while reducing GHG emissions and WF are effective measures to achieve high crop productivity with minimum environmental impact (i.e. a multi-pronged approach of sustainable intensification (SI) and climate-smart agriculture (CSA) to achieve food security). In conventional agricultural systems, intensive soil tillage and removal of crop residues can lead to increase negative environmental impact due to reduce SOC, GHG emission and high water consumption. Conservation agriculture (CA) based conservation tillage systems (CTS) with crop residue retention is often suggested as a resource conserving alternative to increase crop productivity without compromising soil health and environmental sustainability of cereal cropping systems. The environmental impact of CTS in terms of SOC, WF and GHG emissions nonetheless remains understudied in Bangladesh. A two-year field experiment was carried out to evaluate the impacts of CTS with retention of crop residue on SOC accumulation, GHG emission and WF in wheat cultivation of Bangladesh. In the experiment, CTS such as zero tillage (ZT) and minimum tillage (MT) were compared with the conventional tillage (CT) practice. Result observed that the SOC accumulation in the soil was 0.11 t ha−1, 0.97 t ha−1, and 1.3 t ha−1 for CT, MT and ZT practices, respectively. A life cycle GHG emission estimation by farm efficiency analysis tool (FEAT) calculated 1987, 1992 and 2028 kg CO2eq ha−1 for ZT, MT and CT practices, respectively. Among the studied tillage options, lowest WF was achieved by MT (570.05 m3 t−1) followed by ZT (578.56 m3 t−1) and CT (608.85 m3 t−1). Since the results are in favor of CTS, this study recommends MT and ZT practice to reduce negative environmental externalities in wheat cultivation in Bangladesh. In comparison between the methods, the MT, which retains crop residue (20 cm), and involves principles of CA, is suitable for both CSA and SI of wheat cultivation in Bangladesh due to its ability to increase SOC accumulation, prevent both water loss, and GHG emission without compromising yield.

Strategies for agricultural production management based on land, water and carbon footprints on the Qinghai-Tibet Plateau

Future of food: Innovating towards sustainable healthy diets

1. A total of 720 1-d-old broilers were used in a 28 d experiment to determine the effects of probiotic supplementation in diets with different dietary nutrient densities.2. Birds were randomly allotted to one of the 4 treatments in a 2 × 2 factorial arrangement (12 replicateswith 15 broilers per replicate) with two levels of nutrient density [high nutrient density (metabolisable energy (ME) 12.7 MJ/kg and crude protein (CP) 230.3 g/kg for 1–7 d; ME 13.2 MJ/kg and CP 220.3 g/kg for 8–28 d) or low nutrient density (ME 12.1 MJ/kg and CP 220.2 g/kg for 0–7 d; ME 12.6 MJ/kg and CP 209.8 g/kg for 8–28 d)] and 0 or 2 g/kg probiotics (1.0 × 1010 viable spores/g of Bacillus subtilis endospores and 1.0 × 109 viable spores/g of Clostridium butyricum).3. The high-nutrient-density diet increased body weight gain (BWG), feed conversion ratio (FCR), serum cholesterol and triglyceride concentration relative to the low-nutrient-density diet. High-nutrient-density diet reduced water loss ratio of breast muscle, liver and fat relative to body weight compared to low-nutrient density-diet. The inclusion of probiotics increased BWG and feed intake throughout the experiment. Dietary probiotics increased the percentage of blood lymphocytes and relative weight of spleen and bursa of Fabricius when compared to the non-probiotic treatment. The inclusion of probiotics decreased serum cholesterol and triglyceride concentrations and lightness (L*) value of breast meat compared to the non-probiotic-supplemented diet.4. In conclusion, high dietary nutrient density increased growth performance and serum cholesterol and triglyceride concentrations in broiler chickens. The inclusion of probiotics increased growth performance but reduced serum cholesterol and triglyceride concentrations. The positive effect of probiotic supplementation on growth performance was reduced by the high-nutrient-density diet during the first week of life.

Natural resources are consumed in food production, and food loss is consequently accompanied with a loss of resources as well as greenhouse gas (GHG) emissions. This study analyses food loss based on India-specific production data (for the year 2013) and reported food loss rates during production and post-harvest stages of major food crops and animal products in India. Further, the study evaluates the environmental impacts of food loss in terms of utilization of water, land resources and GHG emissions. The total food loss in harvest and post-harvest stages of the food supply chain for the selected food items amounted to 58.3 ± 2.22 million tonnes (Mt) in the year 2013 with the highest losses by mass in sugarcane and rice. The volume of water associated with the food losses was found to be 115 ± 4.15 billion m3, of which 105 ± 3.77 billion m3 was direct water use (blue + green) and 9.54 ± 0.38 billion m3 was indirect water use (grey). Wasted sugarcane and rice were found to be the largest contributors for water loss. Land footprint and carbon footprint associated with food loss were found to be 9.58 ± 0.4 million hectares (Mha) and 64.1 ± 3.8 Mt CO2eq, respectively, with rice accounting for the largest impact in both. This highlights the immediate need for quantification and taking measures for minimization of losses across the food supply chains in India.