Water scarcity is already a reality. More food will be required for a growing and wealthier and urbanized population that will put more pressure on water resources. With several water-related limits reached or breached - groundwater decline, shrinking rivers and threatened fisheries - we must ask, Will there be enough water to grow enough food? It is possible to produce the food needed, but if present practices continue it is not probable that we will solve the many poverty and environmental challenges confronting us. To share a scarce resource and to limit environmental damage in the face of climate change, it is imperative to limit future water use. Important pathways to growing enough food with limited water are to increase productivity of water in irrigated and rainfed areas, improve water management in low-yielding rainfed areas, and to consider our own food consumption patterns. In pockets of poverty in sub-Saharan Africa and Asia, expanding access to water through a range of water management solutions holds the key to food security and poverty reduction. For sustainable water use, water managers must consider agriculture as an ecosystem and how other ecosystem services are impacted through water. These actions will require serious changes in how we think about water and food, and how we govern water and land resources.

Cities are complex and evolving systems with various factors playing key roles, e.g., population increase, the migration of population, the availability of resources, and the flexibility of policies. Consumers’ socioeconomic status is also an important aspect that needs to be studied in the context of a self-reliant urban city in its resource consumption. In this regard, the association between water–food and socio-economic attributes was analyzed based on the consumer-centric approach for the Hyderabad Metro Development Authority (HMDA) region, India. In this study, the embedded water content in food consumption was estimated and analyzed for nine food groups and twelve economic classes of the HMDA region. The middle economic classes were found to correspond to ~80% of embedded water content in the HMDA region, followed by the upper and lower economic classes. Except for cereals, per capita, the water consumption of all food groups increased with the spending power of the economic class. The green, blue, and grey consumption water footprints (WFs) suggested that much of the water that is being consumed in the HMDA region is precipitation-driven, followed by surface and groundwater resources. Limited water resources, water resource variability, climate change consequences including future climate projections, uncertainty in data, WF estimates, and region’s future growth imply a detailed study in drafting policies to become a self-reliant region.

Cities are complex and evolving systems with various factors playing key roles, e.g., population increase, the migration of population, the availability of resources, and the flexibility of policies. Consumers’ socioeconomic status is also an important aspect that needs to be studied in the context of a self-reliant urban city in its resource consumption. In this regard, the association between water–food and socio-economic attributes was analyzed based on the consumer-centric approach for the Hyderabad Metro Development Authority (HMDA) region, India. In this study, the embedded water content in food consumption was estimated and analyzed for nine food groups and twelve economic classes of the HMDA region. The middle economic classes were found to correspond to ~80% of embedded water content in the HMDA region, followed by the upper and lower economic classes. Except for cereals, per capita, the water consumption of all food groups increased with the spending power of the economic class. The green, blue, and grey consumption water footprints (WFs) suggested that much of the water that is being consumed in the HMDA region is precipitation-driven, followed by surface and groundwater resources. Limited water resources, water resource variability, climate change consequences including future climate projections, uncertainty in data, WF estimates, and region’s future growth imply a detailed study in drafting policies to become a self-reliant region.

Over the next few years, Tunisia will face a growing scarcity of water. The concept of a food consumption water footprint has been recently applied to expand knowledge about water management and to respond to problems of food insecurity. In this study, following the Water Footprint Network (WFN) method, we assessed and analysed the food consumption water footprint of Tunisian households by geographical location and by group of food products. We used results from national food surveys to collect the quantities of food consumed and the WFN database containing water footprints of food products specific to Tunisia. We found that the average water footprint for the main consumed food groups has increased by 31% during recent decades, from 1208 m³/capita/year in 1985 to 1586 m³/capita/year in 2010. Despite the decline in cereal consumption in Tunisia, the food water footprint has continued to rise as a result of increased consumption of animal source products. This increase is associated with regional variations in food choices that imply large differences in water footprints. Urban diets present higher water footprints than rural diets proportionally to higher standards of living. This study provides a new perspective on the water footprint of food consumption in Tunisia by using dietary data at the household level and demonstrated significant variability in water footprints due to different food consumption modes, and socio-economic and geographic characteristics. Future food consumption trends will likely create more pressure on water resources, especially in Tunis city and coastal areas of Tunisia. Special measures related to price policies, sensitization of consumers, and changes in production systems may have to be taken by policy makers to reduce the water footprint in order to improve food security strategies and water management in Tunisia.

The challenge of feeding nine billion people by 2050, in a context of constrained resources and growing environmental pressures posed by current food production methods on one side, and changing lifestyles and consequent shifts in dietary patterns on the other, exacerbated by the effects of climate change, has been defined as one of the biggest challenges of the 21st century. The first step to achieve food security is to find a balance between the growing demand for food, and the limited production capacity. In order to do this three main pathways have been identified: employing sustainable production methods in agriculture, changing diets, and reducing waste in all stages of the food chain. The application of an energy, water and food nexus (EWFN) approach, which takes into account the interactions and connections between these three resources, and the synergies and trade-offs that arise from the way they are managed, is a prerequisite for the correct application of these pathways. This work discusses how Life Cycle Assessment (LCA) might be applicable for creating the evidence-base to foster such desired shifts in food production and consumption patterns.

This research study shows that ‘business-as-usual’ scenarios will have substantial production surpluses of rice, which dominates water use patterns in the country at present. However, the surpluses come at a considerable environmental cost, due to high levels of groundwater depletion. Bangladesh can mitigate potential groundwater crises by limiting rice production to meet the requirements of self-sufficiency. Increases in water productivity of both Aman (wet season) and Boro (dry season) rice production can help too. A carefully designed deficit irrigation regime for Boro rice can also increase transpiration, yield, water productivity and production, and reduce the pressure on scarce groundwater resources.

This research study shows that ‘business-as-usual’ scenarios will have substantial production surpluses of rice, which dominates water use patterns in the country at present. However, the surpluses come at a considerable environmental cost, due to high levels of groundwater depletion. Bangladesh can mitigate potential groundwater crises by limiting rice production to meet the requirements of self-sufficiency. Increases in water productivity of both Aman (wet season) and Boro (dry season) rice production can help too. A carefully designed deficit irrigation regime for Boro rice can also increase transpiration, yield, water productivity and production, and reduce the pressure on scarce groundwater resources.

A study of 20 healthy young male volunteers confirmed the existence of a quantitative and temporal relationship between food and fluid intake, and assessed the effects of fluid restriction on food acceptability and intake under scheduled eating conditions. Fluid restriction and thirst were significantly correlated with a reduction of food intake. Possible explanations of the relation between food and fluid intake are discussed.

Water shortages are a worldwide problem. Virtual water and the water footprint link water resources, human beings and agricultural products, and are effective tools to alleviate water-resources stress. The production of agricultural products consumes a large amount of water, and food is the most basic consumer good for human survival, so it is very necessary to study the water footprint of residents&rsquo: food consumption, which is also the weak point of current research on virtual water and the water footprint. This paper aimed to conduct a comprehensive analysis on the water footprint of food consumption in China from the perspectives of urban and rural residents, per capita water footprint, water footprint structure and food consumption structure. The results revealed that the average water footprint of residents&rsquo: food consumption was 605.12 billion m3/year, basically showing an upward trend. Guangdong residents had the highest water footprint for food consumption due to the highest population and higher consumption of water-intensive foodstuffs such as grain and meat in their diet. The water footprint of Xizang residents&rsquo: food consumption was the lowest followed by Ningxia and Qinghai due to having the least population. The water footprint of food consumption consumed by urban residents was on the rise while that consumed by rural residents was on the decline in China, which was consistent with the changing trend of population. On the whole, the rural population consumed more virtual water embedded in food than the urban population. From the water footprint structure point, the contribution rate of the green water footprint is the largest, reaching 69.36%. The second is the gray water footprint and then the blue water footprint, accounting for 18.71% and 11.93%, respectively. From the perspective of the food consumption structure, grain and pig, beef and mutton consumption contributed significantly to the total water footprint of residents&rsquo: food consumption, contributing 37.5% and 22.56%, respectively. The study is helpful for water management and water allocation in rural and urban areas, improving agricultural technology to reduce the gray water footprint and optimizing food consumption structure, such as reducing the consumption of grain and meat.

While agriculture places the greatest demand on water resources, increasing agricultural production is worsening a global water shortage. Reducing the cultivation of water-consuming crops may be the most effective way to reduce agricultural water use. However, when also taking food demand into consideration, sustaining the balance between regional water and food securities is a growing challenge. This paper addresses this task for regions where water is unsustainable for food production (Beijing-Tianjin-Hebei Region for example) by: (i) assessing the different effects of wheat and maize on water use; (ii) analyzing virtual water and virtual land flows associated with food imports and exports between Beijing-Tianjin-Hebei and elsewhere in China; (iii) identifying sub-regions where grain is produced using scarce water resources but exported to other regions; and (iv) analyzing the potentiality for mitigating water shortage via Land-Water-Food Nexus. In the Beijing-Tianjin-Hebei Region, the study reveals that 29.76 bn m3 of virtual water (10.81 bn m3 of blue virtual water) are used by wheat and maize production and 8.77 bn m3 of virtual water used in nearly 2 million ha of cropland to overproduce 12 million ton of maize for external food consumption. As an importing-based sub-region with high population density, Beijing & Tianjin imported mostly grain (wheat and maize) from Shandong Province. Then, Hebei Province, as an exporting-based sub-region with severe water shortage, overproduced too much grain for other regions, which aggravated the water crisis. To achieve an integrated and sustainable development of the Beijing-Tianjin-Hebei Region, Hebei Province should stop undertaking the breadbasket role for Beijing & Tianjin and pay more attention to groundwater depletion. The analysis of the Land-Water-Food Nexus indicates how shifts in cultivated crops can potentially solve the overuse of water resources without adverse effects on food supply. It also provides meaningful information to support policy decisions about regional cropping strategies.