It’s dinner time and you’re shattered. You have a fridge full of food but lack the willpower to cook. Maybe you will just go out to eat, or crack open a ready meal from the freezer. Problem is, you are trying to be healthy, and make better decisions for the planet. What to do?
When it comes to your health, it is perhaps unsurprising that there is growing evidence to suggest cooking food at home is better for you than eating out.
For instance, a study of 9500 adults found that people who cooked regularly ate fewer calories, and less sugar and fat, than people who mostly ate out (). Another study published this year found a similar pattern, and also noted that home chefs tended to spend less on food ().
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It’s all very well worrying about your own health, but what about the health of the planet?
The production of food takes a huge environmental toll. Globally, food production occupies over a third of Earth’s land surface and creates . So is it better to cook at home, or to eat out – or, for that matter, to buy industrially produced ready meals?
Waste of potatoes
“Most people assume that home cooking is beneficial from an environmental point of view, but you could ask why,” says of the Research Institutes of Sweden. He offers a different way of looking at it: “Home cooking is food processing done in ill-equipped small-scale facilities, by non-skilled staff, with limited possibilities to efficiently use by-products. Why should that be better than efficient large-scale processing?”
To try to answer these kinds of questions, environmental scientists use life cycle analysis (LCA): a method for tracking all the resources that are used, and wastes released, when a product is made. It is essentially a kind of accounting. In the case of a meal, an LCA needs to cover everything from the farms where the ingredients were grown, the vehicles that transported them, the energy and water used in preparing them and any wastes such as leftovers or packaging.
In a 2005 study, Sonesson and his colleagues used LCA to examine three different ways of preparing the same meal: the Swedish classic of meatballs with mashed potatoes, bread and carrots. They compared a ready meal, a home-cooked version and a semi-prepared version that was cooked at home using chilled meatballs and mashed potato powder.
The three methods were about equally efficient in their use of raw materials, except that home cooking proved much more wasteful of potatoes. Home cooking did tend to use less energy, but it produced more greenhouse gases ().
So, ready meals might be surprisingly environmentally friendly, even though they use more packaging than home cooking. What about restaurants?
Eating out in doubt
Earlier this year, in what appears to be the only published LCA that compares home cooking with restaurant dining, of the University of Oviedo in Spain and his colleagues examined a Spanish stew made with broad beans, sausages and ham. They studied four ways of making it: home cooking, restaurant cooking, a catering company that made large quantities of the dish and an industrially-produced canned version.
Overall, the two largest-scale methods had lower environmental footprints. The restaurant came out worst, particularly in its carbon footprint, but that was partly because all of its energy use – including lighting the dining area – was counted against it (). Home cooking fared better, and on some measures was about as good as the larger-scale methods.
That is not exactly a ringing endorsement of home cooking, but perhaps we could do it better.
Sonesson has explored how foods might be made more sustainable by comparing different ways of making a simple meal of chicken and potatoes (). Two key choices were taking fewer trips to the supermarket – thus reducing greenhouse gas emissions from one’s car – and wasting less food. These improvements could be made regardless of whether the food was purely home-cooked or semi-prepared.
All in all, there is not a lot of published data on the environmental effects of different ways of eating – and what there is offers a mixed picture. It seems it is wrong to assume that home cooking is particularly sustainable, although it’s arguably better than restaurants.
Still, as Sonesson points out, there are “very good reasons to cook at home”: it improves your connection to food and it’s generally cheaper and better for your health. “But,” he says, “environmental efficiency is not one of them.”
