For many people Christmas is about eating and drinking but it is easy to get carried away, not just eating too much but buying too much, and then throwing it away.
“It only lasts a couple of days so don’t shop as if you are under siege for a month,” says Rob Percival, the Soil Association’s head of food policy.
“Resist the temptation to buy a huge turkey you will never finish and which will end up in the bin once you have exhausted ideas to use up the leftovers.”
Around the world, households discard 74kg of food a person, according to data from the UN, and food waste and loss causes about 10% of the emissions driving the climate emergency. If food waste was a country, it would have the third highest emissions after only the US and China.
“We’re too casual about throwing away food,” says Marija Rompani, director of ethics and sustainability at John Lewis Partnership, which owns Waitrose.
“The reality is food waste creates six times more greenhouse gases than aviation. When we throw food away, we waste the precious resources taken to grow, package and transport it – and as it rots in landfill, it produces methane, a greenhouse gas more potent than carbon dioxide. So the simple action of throwing food in the bin has more of a negative impact on our planet than people often realise.”
Spend time thinking about the number of people you are catering for, and work out exactly how many meals you will have to prepare. Remember to take into account that some will be made up of leftovers from the main Christmas dinner.
Kendall Zaluski, chef tutor at the Waitrose Cookery School in central London, says: “If you’re keeping it traditional, and opting for turkey, buy the right size for the number of people you’ll be cooking for. Waitrose clearly states on the pack how many people it will serve.”
Many other suppliers offer that kind of guidance, or, if you are buying from a butcher, they should be able to advise you.
Online, too, you can easily find information on what sized roast you need for the number of people you are catering for.
For anyone trying to reduce their environmental footprint, eating less and better meat is a simple mantra to follow.
Most turkeys eaten in December are intensively reared indoors and fed cheap soya, which is linked to deforestation, so it is important to select your bird carefully. If you can afford to, the Soil Association urges shoppers to buy an organic bird or consider other proteins.
At a time when food prices are rising anyway, going organic comes at a price. The birds cost more, and worker shortages bedevilling the industry mean you probably need to order well in advance.
“If an organic bird is not feasible then look at welfare-assured and free-range options,” says Percival. “If you are buying a barn-reared turkey then look for a Bronze bird, which has been more slowly reared in less crowded conditions.”
At Tesco, for example, a basic turkey crown is listed online at £7.95 a kilo, while free range costs £15 a kilo and organic is £19 a kilo.
If these alternatives don’t work, consider pasture-fed beef or lamb, or ditch meat altogether for a vegetarian or vegan centrepiece.
Another way to limit the environmental impact of your dinner is to avoid exotic veg. Just stick to traditional accompaniments such as spuds, sprouts, carrots, leeks and parsnips, which are in season.
If you can, buy loose veg so as to reduce packaging and get the exact quantities that you need.
If you need help working out how much to buy, Zaluski suggests you allow one large handful of greens for each person, and two root veg, such as carrots or parsnips. She thinks one large potato each is enough (with maybe an extra thrown in for every fourth person, just in case).
Another festive favourite, cheese, has a high carbon footprint so go easy when stocking up the fridge.
All is not lost if you have lots of turkey left over, Zaluski says. It is a versatile food to incorporate in other meals with the carcass perfect as the base for stocks or gravy: “I like to roast the carcass for a more intense flavour. This is a great way to yield as much flavour as possible, as the roasting caramelises the tiny bits of meat still attached.”
Another way to make greener choices about what you eat over the festive period is to seek out B-Corp certified food and drink brands.
On both the Ocado and Waitrose websites you can browse virtual aisles dedicated to thousands of products, including beer, wine, spirits and chocolates, from companies that are part of the ethical scheme.