The United Nations Food and Agriculture Organization and the World Health Organization are meeting this week to discuss the UN Decade of Action on Nutrition. In this issue, we publish two Comment articles that look at some of the problems. In one piece, a group of researchers stresses the importance of nourishing people, not just feeding them. And the other calls for a better approach to quantifying and analysing different aspects of the food-production system.

Between one-fifth and one-third of all food produced goes into the bin. Attention has increased on these post-harvest losses in recent years, and this week the European Commission held what it billed as the first European Union Platform on Food Losses and Food Waste. Launching the event with a speech that will be recognized by any parent who has sat with a child who won’t clear their plate, commissioner Vytenis Andriukaitis said: “It is shameful to throw away food in the world where more than eight hundred million people go to bed hungry.”

To help promote responsible development and production of food, the UN global Sustainable Development Goals call for a number of related measures, one of which is to halve waste in the commercial and retail sectors by 2030. It is partly a consumer challenge, because a sizeable chunk of this thrown-away food has been bought and paid for, sometimes at great expense. To many US readers, it will be second nature to take restaurant leftovers home. That helps to reduce waste, even if some of the contents of the doggy bag end up in, well, the dog.

In countries such as France it’s a different story. The government there has been trying to change that, with a new initiative this year that requires restaurants to supply a ‘gourmet bag’ to diners if they ask for one. Not everyone is happy about the idea, and new research offers some pointers why. The results demonstrate, again, the importance of cultural and social factors in shifting behaviour — even in a direction that benefits all concerned.

Writing in the Journal of Retailing and Consumer Services, researchers describe interviews with French diners about their attitudes to food waste and taking it home with them (L. Sirieix et al. J. Retail. Consum. Serv. 34, 153–158; 2017). They found the now-standard gap between attitudes and behaviour on environmental issues: although three-quarters of respondents thought that doggy bags were a great idea, just one in ten had ever asked for one.

The excuses were many. “It comes from history and French customs,” one said. Another argued that leaving expensive food on the plate showed social status: “Someone who will take home the meal is someone who has less money.” And it was a sign of a downmarket joint: “It will not be well accepted in a fine dining restaurant.”

Diners went further. Asking for leftovers would bring shame. “It’s not rude but culturally it’s not normal.” And French dishes are just not designed to be eaten that way, they said. It’s “too good to be packed” and only acceptable in “a pizzeria”.

One solution, the researchers suggest, is to make the doggy bag desirable: a valuable gift that appeals on more levels than just sustainability. Some high-end restaurants in the United States, they note, package leftovers in a foil swan. That’s one possible solution. Another, of course, is simply to serve smaller portions.