Accounting for a more sustainable future

Middle classes in the western world are increasingly mindful of what they eat and where their food comes from – driving a shift toward plant-based diets that are perceived to be healthier and better for the environment. But this is of course not an option for many. Yes, we have to change, but we need to consider society and the planet as a whole and factor in those on lower incomes without access to the breadth of plant-based foods available in the west.

To get the protein we need from a plant-based diet, variety is essential but this is difficult in parts of the world limited to one or two crops. Meat is therefore likely to continue playing a role in our diets, particularly in poorer countries and communities. As the global population rises (by 2050 we'll have 9.7 billion people on the planet) we need to approach feeding the world as efficiently and sustainably as possible.

There is consensus that we need to cut our meat consumption to limit our impact on the environment; in the west we currently eat two-thirds more protein than we need to. Rather than taking an absolutist view on cutting meat, a more pragmatic approach is to view meat as a protein supplement to a plant-focussed diet. Research has shown that, from an environmental perspective, we are better off being two thirds vegetarian rather than wholly vegan. We need animals in the ecosystem - and responsible grazing methods can actually increase soil health.

Levels of malnutrition in rich and poor countries make meat a cost-effective and viable way of maintaining a balanced diet. Malnutrition comes in many forms (e.g. protein, calorie, nutrient) and isn't limited to the developing world; For example, a third of people in UK care homes are considered malnourished.

We also have to contend with growing seasons. The UK 'hunger gap' is May and June, the hardest time to harvest vegetables, making meat a practical source of calories.

There's no disputing the rise in veganism over recent years. But where do you draw the line? Are oysters vegan?

If you look at the reasons for veganism - ethics, environment and health - how do you define what is acceptable? Oysters have no brain or advanced central nervous system, so it's likely they don't feel pain, and they produce protein from a source we can't necessarily eat (algae and plankton). 95% of oysters are farmed and have a minimal impact on the environment (e.g. they're not dredged from the seabed, don't require deforestation) and can actually improve water quality. From a health perspective they're loaded with protein, omega 3 fatty acids, zinc, iron, selenium and vitamins B12 and D. It's a hotly contested issue, and one on which our panelists couldn't agree.

Rearing meat on mixed farms has traditionally been an important source of fertiliser. In a world where meat consumption is on the decline, human waste could be the smelly answer to the problem. Cities have it in abundance; using it in compost directs waste away from oceans and landfill and delivers much needed plant nutrients to the soil. A future without squeamishness may be a necessity. There are considerations around the presence of heavy metals, pharmaceuticals and hormones, but water treatment is now very effective at filtering these out and the use of human manure is tightly controlled.

Food trends can be as damaging as meat consumption. The on-trend salad and the necessity for ‘fresh' can drive unsustainable farming practices and dangerous monoculture. Take the humble cucumber for example, something we eat in our salads year-round. In the UK we used to have 50 - 60 varieties of cucumber – now we have one dominant type, the long burpee. In the US, we've lost 96% of the corn varieties we had at the beginning of the 20th century.

More variety means mitigating changes in climate – what's good for one type is bad for others. It also means extending the growing season, as different varieties are ready for harvest at different times.

Diversity leads to more sustainable farming practices. As consumers, we shouldn't be wedded to always eating fresh, straight, green cucumbers, but should be open to yellow, curved and preserved produce. It also requires agricultural and seed businesses to offer the variety needed by farmers.

While there's a move to low waste restaurants and vegetarian dishes, to prepare this kind of food requires a huge amount of skill, for example butchering and using the whole animal, or being creative with veg. Many restaurants now buy in specific portions e.g. fillets of salmon or chicken breasts, rather than whole animals. We're seeing a generation of chefs coming through who simply haven't seen a whole animal, let alone learned how to balance a profitable menu around it.

The need extends to home cooking also. In a world of convenience, we need to plug the skills gap or find accessible ways for consumers of all skills and budgets to cook healthy affordable meals with minimal impact on the environment.

Yes, pickling and fermenting is all the rage, but this is clearly not a viable solution for everyone. Freezing technology has quietly leaped forward – preserving food and its nutrition for months or years. Looking to the future, we need to kick frozen food prejudices and reconfigure our kitchens – shrinking our fridges for smaller fresh shops and bringing back the giant freezers of the 70's (though obviously they're significantly more energy efficient these days), to reduce the burden on farmers while maintaining a supply of quality food.

Processing also has advantages beyond preservation. Yes it was developed to preserve food for longer, but many fresh foods, including vegetables, also contain anti-nutrients which can block nutrient absorption; these are broken down during processing.

Genetically modified crops have received a bad press. But as the climate changes, the planet will warm and we will need hardier, drought-resistant crops – GM offers a viable and readily available solution. It's time for a fresh perspective on the technology. We need to bust the myths and consider where it fits in the future of food.

Why are meat products and plant-based protein products in separate aisles in our supermarkets? For millennia, meat has been central to our meals. To move away from meat as a staple, we need to change the way we think about what constitutes a meal – wearing down the distinction between meat and non-meat products. Eating more plant-based foods or meat alternatives is an important piece in the puzzle. It won't happen overnight, but incremental change in how we think about food will make a world of difference to future generations.

It's a balance between restaurants forcing change through choice and consumers altering their expectations. Beyond getting creative with waste, kitchens are exploring using locally sourced ingredients in new ways. At one of Rebecca Mascarenhas's west London restaurants they use fig leaves from local trees to make ice cream and have a bartering system with allotment owners. Allotment producers can't sell their produce, it's against their charter, but if they have more than they can eat of a certain crop then the chef will take the surplus and offer restaurant credit in return.