Often considered “the elephant in the room,” some of the old prophecies on the existence of biophysical limits to population growth are going to be central in the analysis of the future of food security . It has been argued that there is an urgent need to contain the escalating demand for food commodities by stabilizing the global population . This has revamped the debate on the efficacy of population policies and reproductive health education , as well as other longer-term approaches based on both social and economic development, including empowerment of women and access to education, poverty eradication, and other factors affecting fertility rates .Though food supply may be adequate at the global scale, high levels of undernourishment persist in many parts of the developing world , while habits of over consumption have become commonplace in the United States and Europe . Thus, in addition to production-side solutions that have been proposed for meeting future demand, recent work has pointed toward the need for efforts to draw down per capita demand , particularly in countries with diets with a large fraction from animal products, and to promote better physical and economic access for less integrated markets. Approaches to promote a shift toward healthier and environmentally more sustainable diets can be based on a variety of interventions, including raising awareness, education, “nudge” methods ,plant benches economic incentives, taxation , and law restrictions. The latter three approaches, however, can be difficult to accept in free market economies and liberal societies .
Although a consumption focused approach to food security may be difficult to implement, given the social and cultural associations of diets, new studies have demonstrated linkages between sustainable dietary choices and health and explored sustainable diets. Thus, approaches based on health awareness can also improve environmental sustainability. Other strategies to enhance awareness and education rely on the effect of sustainability labels on food choices or rely on academic institutions to take the lead in evaluating and improving the water, carbon, and nitrogen footprints of the institutions, starting with the food served . Indeed, universities and other nonprofit organizations can be leaders in developing internal food sustainability policies and, in doing so, set the standards for other institutions in a manner similar to that of major divestment initiatives in “unethical” businesses related to apartheid, tobacco, or fossil fuels. Such divestment efforts started from the management of endowments of major university and religious organizations and spread to the broader market . Presently, universities are pioneering efforts aimed at calculating and reducing the nitrogen, carbon, and water footprints within their institutions or promoting low meat diets . There are, however, some major barriers to a dietary shift away from a meat-based diet. The greatest barriers are cultural and are associated with the appreciation of meat by those who are used to having it as the central part of their meals, enjoy its taste, lack knowledge about how to prepare vegetarian meals, or believe that meat has a higher nutritional value than other food types. Moreover, in many societies meat consumption is perceived as a sign of affluence, status, masculinity, authority, and physical strength . These cultural factors shape a society’s consumption patterns and make dietary shifts a difficult task .
Appreciation for meat is typically stronger among men, younger people, families with children, and rural communities in which meat consumption is considered an important part of their tradition, whereas plant-based diets are perceived to have no taste or nutrition value . Knowledge gaps about the environmental and health impacts of meat, and false perceptions about the nutritional properties of vegetables, can constitute important barriers to a shift toward diets that use less meat. There is also a generalized reluctance to the use of meat substitutes because of unfamiliarity with their taste and texture, and many people do not know how to replace meat with proteins from vegetable sources . Although cultural barriers are hard to remove, some of the knowledge gaps listed above could be addressed by educating citizens about the nutritional, health, and environmental implications of their food consumption habits. Attempts at promoting dietary shifts could be more effective if they target specific social groups―namely, the student population, who could start getting used to meat substitutes at a young age; women, who appear to be more inclined to vegetarian diets than men ; or citizens concerned about the health impacts of an excessive use of meat . Other educational initiatives could appeal to concerns about environmental impacts, animal ethics, and welfare . New policies could promote healthier and sustainable diets by setting higher nutritional and environmental standards for school meals . To reduce meat consumption some school districts and workplaces are already adopting meat-free days in their meal plans, while promoting health education to decrease employers’ long-term healthcare costs. In some affluent countries, there are already signs of reduced meat consumption, which indicates that, as societies become wealthier, concerns about health and environment lead to a more moderate consumption of meat, according to a Kuznet-like inverted-U curve . Reductions in meat consumption can be favored by urbanization, education, empowerment of women, or the use of sustainability labels . In the developing world, however, the expected trend is still that of an increase in meat consumption in the next few decades.For instance, less sustainable food types, such as meat or unhealthy processed foods could be taxed, whereas subsidies could be used to reduce the prices of vegetables, meat substitutes, and other more sustainable and healthier food products.
Such policies could ensure that food prices account for environmental costs and use part of the tax revenues for the improvement of taste, texture, and nutritional properties of meat substitutes . The efficacy of policies acting on food prices, however, could be modest in affluent societies where only a relatively small fraction of the income is typically spent on food, a pattern known as Engel’s law.Trends toward greater animal protein in diets mean that livestock production systems need to become far more efficient. In this regard, the ongoing transition toward monogastric production is encouraging. Indeed, recent work has shown that shifting grain-fed beef production entirely to chicken and pork production would feed an additional 367 million people . As with closing crop yield gaps, the industrialization of animal production poses a huge challenge to the sector’s vital and ongoing role in poverty alleviation because livestock, and agriculture in general, are important for various aspects of rural livelihoods . Likewise, the expansion of sustainable forms of aquaculture offers an alternative, and potentially more environmentally sustainable, way to meet some of this future demand for animal products . Even more so than for crop production, the future of the livestock sector is far from clear . The last few decades have seen an increasing reliance on poultry and swine meat, and a decrease in the fraction of ruminant meat consumption, worldwide . This trend allows for a reduction of the land used and carbon footprints of meat per unit calorie .As noted in the previous sections, a possible approach to feed the world with the limited resources of the planet is to reduce the consumption of meat, particularly of the meat types that have the greater environmental footprints. Alexander et al. reviewed a series of alternative meat types,rolling bench including insects, cultured meats , and imitation meats; they found that insects and imitation meats had particularly low land use requirements relative to conventional meat. However, imitation meats had relatively minor reductions in land use requirements compared to poultry and dairy, further emphasizing the importance of dietary change and waste reductions . Other studies have highlighted the environmental, health and economic benefits of eating insects . Most insects have relatively high bio-conversion rates , close to 5 times those of cattle. Moreover, the edible biomass fraction is much higher in insects than in livestock . Therefore, the feed-to-edible meat ratio is much more favorable for insects than for livestock, which explains their smaller land and carbon footprints . Insect meat is also healthier because of its high protein and low fat contents. Further, because insect production requires low technological inputs, it can be practiced by small-scale farmers, thereby improving the food security and nutrition of rural populations, as well as their livelihoods . Insects may be used either for direct human consumption or as feed for the aquaculture and livestock industries. The feed used for insect production can be based on various types of organic waste, including cellulosic materials. Therefore, reliance on insect meat may allow for an effective recycling of waste and favor the establishment of a circular economy , whereby food waste is turned into protein-rich feed and food .
As noted in section 2, about 24% of global food production for human consumption is lost or wasted through the food supply chain . Recent work has demonstrated the environmental benefits of reducing food waste and shown that consumer waste of animal products is particularly costly in terms of land use and crop production . All of these studies provide important insights into how consumers may consider healthier and less environmentally burdensome consumption choices . It has been estimated that food waste accounts for 23% of the arable land, 24% of freshwater resources used for crop production, and an amount of food per capita of roughly 625 kcal per cap per day, including large quantities of nutrients, micro-nutrients, and minerals . These figures speak for themselves. A strategy aimed at improving the use of land and water for food production needs to invest in food waste reduction and reuse. Many studies have investigated how food waste can be reduced by removing inefficiencies in the food supply chain from agricultural production to post harvest storage, processing, distribution, and consumption. Possible actions include crop production planning to avoid surpluses that cannot be placed on the market; improvements in storage, refrigeration, and transportation facilities, particularly in the developing world; changes in the logistics of food retailing and distribution to account for the limited shelf life of perishable products; and consumer education on how to make more effective purchase plans and deal with “expiration” and “sell-by” dates . In developed countries, some of the quality standards for fresh produce overemphasize aesthetic criteria and idealizations about fruit or vegetable size and shape, or product uniformity with the effect of discarding products that are perfectly healthy and edible. Consumer education could encourage the use of substandard or unappealing food products, and products that are unsuitable for human consumption could be repurposed and used as animal feed or for bio-energy production . Food waste can also be contributed to by retailer overbuying, oversized packages, and stores’ compliance with “sell-by” or “use-by” dates. To redress some of these factors, it is possible to act at the retailer and distributor level. Of note is France, where a recent law forbids the destruction of unsold food as it approaches its “best by” date. Rather, supermarkets need to donate these products to food bank charities, though the process of food delivery to humanitarian organizations remains a difficult task as it requires timeliness and coordination . The EU Commission has subsequently established a multi-stake holder platform with the explicit task of developing a strategy to reduce food waste. Another particularly important opportunity in the FEW nexus is to enhance the recovery, treatment, and reuse of wastewater. In terms of water scarcity, wastewater offers a potential alternative source of irrigation in some contexts . Improved access to sanitation is not only a UN Sustainable Development Goal in and of itself, but improved sanitation systems offer massive potential to recover critical plant nutrients, particularly P, to offset agricultural nutrient demands at the global scale and, to some degree, to influence household energy goals through renewable sources such as biogas . Recycling of nutrients from urban waste streams is especially important for the P cycle because of the nonrenewable nature of this resource and the relatively high P content of sewage sludge . However, in addition to the infrastructure needed for urban sanitation, multiple socioeconomic and environmental factors can play a role in the efficacy of nutrient recycling in any given city .Despite all the efforts our societies can make to reduce food waste through more efficient food supply chains, consumer education, and the use of food banks, some of the losses existing in the food system are unavoidable.