One-third of food produced for human consumption (1.3 billion tons) is lost or wasted all over the world[1]. Food waste is a huge challenge to global food security. The population is increasing quickly, which contributes to an increase in food demand. People need to realize that many negative impacts of food waste and what drivers food waste, and minimize it to make sure enough food is available to meet growing population demands.

According to FAO[2], food waste is defined as “food appropriate for human consumption being discarded, whether or not after it is kept beyond its expiry date or left to spoil. ” This blog will focus on food waste rather than food loss because in developed countries food waste(consumer sectors) is in higher quantities than food loss(production and processing sectors)[3].屏幕快照 2017-12-02 下午2.34.32

Fig 1 North American food losses at each step in the supply chain

The negative impacts of food waste

It is very important to teach people about negative impacts of food waste in order to change people’s attitudes to it and to shift their food waste behaviors. Here I will talk about four aspects: economic, social, environmental impacts of food production and food waste disposal.

Economic losses

Economic losses influence everyone in food supply chain, so that understand huge costs of food waste may encourage people to change their waste activities. Table 1 shows the financial losses data of food waste.

Table 1 Economic losses of food waste and loss屏幕快照 2017-12-02 下午3.15.08

Food insecurity

According to FAO[4], about 11% of global population is in food insecurity. If we can minimize the food waste and manage food resources better, the food can be used to feed more people who are in hungry. Reynolds et al.  estimated that if all avoidable waste in Australia were donated, it might solve 921,000 people’ food needs for a year[5]. Furthermore, if food waste was reduced, fewer resources will be used to produce the food which is not consumed and these resources such as arable land and water can be used to grow crops for the people in food insecurity[6]. The United Nations estimated that global population will reach 9.3 billion by 2050[7] so that food production needs to increase 70% to meet human demands[8]. Reduction of food waste will be a core part of sustainable and equitable feeding growing population[9].

Environmental impacts of food production and distribution

Food supply system(production, packaging, distribution, and marketing) will affect the environment to harm human, plants, animals, ecosystems[10]. Food production and distribution need a lot of energy and resources. Key environmental risks include water, soil and air such as water pollution and eutrophication. With the food waste, the energy and resources that went into producing, processing are also wasted, leading to needless environmental impacts[1]. 24% of total freshwater used in food production has been estimated to be the production of the loss and waste[11]. The growth of population and food consumption will lead to the higher food demand and environmental pressures. So reducing food waste is an effective way to reduce the environmental impact of the food system on the environment.

Environmental impacts of food waste disposal

The impacts of food waste at the end of its life depend on how it is solved. Food waste will become methane (a strong greenhouse gas) in landfills. Furthermore, food waste tends to degrade faster than other organic matters and has a higher methane yield[12]. Even though one-quarter of American landfills capture methane to produce energy,  the emissions from landfills without collection systems are the third largest source of methane emission in the U.S.[13]. Thus, it is necessary to reduce food waste landfilled.

cow-and-food-waste

Fig 2 Methane and food waste

Drivers of food waste

In fact, food waste has many drivers. In this blog, modernization of food system will be discussed. Modernization’s effects on food system include industrialization, economic growth, urbanization, and globalization and it affects the amount and type of food waste[14].

Industrialization

Firstly, Industrialization contributes to changes from producing food at home to large food factories and from handcraft to purchasing. Therefore, it increases the distance between people and food production and affects the amount and types of food waste. For example, people usually buy pre-cut meats(eg. chicken legs), which leads to waste of other parts of chicken at the consumer level[14].

Economic growth

Higher incomes are associated with a more varied food consumption[15]. Diverse diet may contribute to more food waste, and the more repetitive the diet, the less food wasted[14]. Especially, Asian diets tend to shift toward more Western foods[15]. Western foods are vulnerable and have shorter shelf-life, which may lead to higher food waste[16]. Also with higher incomes, people are more likely to waste food because food costs are not considerable parts of their income. In some wealthy countries, food is relatively cheap compared to other consumption such as housing and people can afford to waste food[17].For instance, Americans spent 19.3 percent of their income on food in 1929; the percentage steadily decreased and in 2016, it was only 6.3 percent[18].

 Urbanization

Urbanization needs to extend food supply systems. The proportion of the world’s population worked in agriculture has reduced and 50 percent of the global population lives in cities and this data is expected to reach 70 percent by 2050[19]. Rapid urbanization needs more food supply chains to feed urban populations. Thus, countries need to improve transportation and marketing infrastructure to ensure that food is affordable for most people. How these extended supply chains develop has impacts on food waste, now and in the future[20].

Globalization

Food systems(quantity, type, cost, variety, and desirability) have changed because of the shift from local to regional to global foods. New food consumption patterns are more global and have many differences from traditional food diet, especially because non-local foods are available, which heavily increases in the range and quantities of available foods[15]. Changes in diets may affect the type of food; people also may tend to waste food as they are lack of a deep connection and understanding of it[14].

In conclusion, the food system is unsustainable and we need to make some changes. Reducing food waste is a necessary way to meet food demands of increasing population.