One in four of the calories we create are never eaten.

In addition to this, the world population is expected to reach 9.1 billion by 2050.

The global food production system needs to be able to keep up with population growth to ensure everyone is fed, but the current food system and associated wasteful practices are a barrier to this goal.

Food is consistently lost or wasted throughout the supply chain, from production to consumption, taking place in supermarkets, restaurants and in the home. Although food recycling has made significant improvements over the years, DEFRA’s most recent statistics on this topic state that 8.7 million tonnes of biodegradable waste - much of it food - was sent to landfill in 2014.

Aside from the the environmental price associated with food waste, there is also an enormous financial cost to this wasteful behaviour. Three major WRAP studies published in 2013 and 2016 estimated annual food waste from UK households, hospitality, food manufacture, retail and wholesale sectors at around 10 million tonnes, 60% of which could have been avoided. This has a value of over £17 billion a year. With financial losses of this kind of scale, it isn’t surprising that forward-thinking businesses are increasingly incorporating sustainable practices in their food sourcing, manufacturing and merchandising.

There is also a clear demand by the general public for a more sustainable food chain, with consumers, media and pressure groups supporting better decisions in relation to their food purchasing habits.

A progress report by Sainsbury's found that consumers also expect retailers to ingrain ethical and environmental sustainability into their products. Justin King, the chief executive of Sainsbury's, stated: “Customers want us to act for them and ask the questions and take the actions they would expect.”

However, despite the environmental knowledge, the business case and the demand for a more sustainable food system, we are still falling short.

In a previous blog post, we referred to the concept of recycling waste protein. Protein is a macronutrient, which means that the body needs relatively large amounts of it. It is an important component of every cell in the body, playing a role in tissue growth and regeneration, in the functioning of enzymes, hormones, bones, muscles, cartilage, skin, and blood. Cycling protein waste streams back into the human diet could prove to be a promising route to further reducing food waste.

Is anyone already recycling food?

There are different ways of recycling waste food, which are appropriate in different circumstances. Moerman’s Ladder provides a hierarchy, from avoiding waste and reusing it at the top, down to landfill at the bottom, and encompassing practices as varied as incineration, composting and animal feed. As a general rule recycling should be at the highest level possible. So if waste food products are good enough for humans to eat, it is perverse to use them to make compost.

This concept of recycling food is not a new one. Staggered by the sheer waste produced by the beer brewing process, a startup called ReGrained is utilising otherwise wasted spent beer grain into beer-flavored, healthy granola bars. A similar story is that of Toast Ale, which creates a pale, malty ale made entirely from surplus bread that would usually be thrown away by bakeries and supermarkets.

There are also the high tech methods to protein valorisation. A biofuel company called Alternative Fuel Corporation (AFC) has found that their ethanol biofuel production process has inadvertently created a nutritious protein-rich form of yeast as a by-product, reportedly suitable for human consumption.

Protein recycling is not a new idea - it’s part of the production of several traditional foodstuffs such as whey cheese, a byproduct of cheesemaking, a sign that recycled protein need not be either highly industrialised products or niche, innovative foods.

Although these examples demonstrate the ways in which valorisation of protein waste is and has been practiced, the food waste issue and lack of mainstream food recycling is systemic.

The current food system lacks widely accepted routes for food to be reused, there are barriers to customer acceptance, and potential pitfalls around regulatory assent. There may also be issues with food safety and traceability, for instance for people with allergies.

Together, these issues mean that a promising source of food that could help feed the world more efficiently - and contribute to saving both money and the environment - is currently not being significantly exploited.

Want to have a say?

On 19 October, the Challenge Prize Centre is holding an expert workshop on the future of food. Whether you’re a scientist working on new ways of processing proteins, an entrepreneur investing in food startups, a chef who experiments with novel foodstuffs or a farmer who wants to reduce their waste, we want your perspective to help us understand this area. Find out more.

More on this issue

Recycled food: Good for the environment and OK for you

Challenges brief: Food innovation

Challenges brief: Animal feed that doesn’t cost the Earth

Challenges brief: Potentials and pitfalls of urban agriculture

This blog appeared originally on the Challenge Prize Centre website.

Image property of the US Department of Food and Agriculture