THURSDAY, May 12, 2022 (HealthDay News) -- Is there a way to make eating out more environmentally friendly? A team of German researchers thinks the answer is a bright green yes.
They'd like restaurants to offer menus that clearly label the environmental impact -- or "carbon footprint" -- of specific meal options.
"In the broadest sense, we asked how restaurant owners can contribute to the struggle against the climate crisis with some kind of 'soft measure' that does not require changing their dish offers," explained study author Benedikt Seger. He's a postdoctoral research scientist with the Department of Psychology at Julius Maximilian University of Würzburg.
For example, a salad that comes with beef would be labeled "high emission." That would mean the meal generates a higher carbon footprint -- perhaps in the range of 2 or even 3 kilograms of carbon dioxide (CO2) -- and is therefore less environmentally friendly.
Alternatively, a vegan spaghetti dish would be labeled "low emission." It would therefore be greener, in that it might produce just 130 grams of CO2.
This information could do a lot to sway diners' restaurant choices.
In their study, investigators put together nine menus in all, reflecting what Seger called "a broad range of restaurant types" that included Chinese, Italian and Indian dishes, alongside American-style burgers.
The menus were offered to just over 250 volunteer diners in an online simulation of an eating out experience, meaning no actual eating was involved.
In some cases the menus came with a twist: default meals the customer could modify to be more or less green, with the addition (or elimination) of components like beef, poultry or falafel.
The result, said Seger, was a big environmental win.
"On average," he noted, "the default 'switches' reduced carbon emissions by 300 grams CO2 per dish. And the labels reduced the emissions by an average 200 grams CO2 per dish."
Seger acknowledged that the choices customers might make when offered similar menus in a real-world setting might be different, as "there will be many other factors that influence the decision, including the presence of other guests and the sight and smell of what they have ordered," he said.
"Nevertheless, these clear results are quite encouraging," Seger said. The findings "show that many people are ready to consider the climate crisis in their everyday decisions, even in contexts where they only want to have a nice time and enjoy their meal."
Seger noted that for this to work, restaurants will need to "take their chances and redesign their menus."
Lona Sandon is program director of clinical nutrition with the School of Health Professions at UT Southwestern Medical Center in Dallas. She suggested that as a practical matter the green menu approach is likely to meet with mixed results.
"It will certainly make a great marketing tool for some restaurants," Sandon said. "I can see some would jump right on board with this."
And among consumers, "there will be some that think this is great and use it to make choices," she added.
At the same time, however, Sandon noted that "others will ignore it just as they ignore the calorie and fat information." And even with both restaurants and consumers on board, there will be the issue of exactly how to determine what a particular meal's carbon footprint really is.
"The food system is very complex," Sandon said. "And the inputs that go into producing and processing a food item varies greatly, and will depend on where it is coming from, and the grower's own practices and ability to limit greenhouse gas production."
For example, "growing zucchini versus beef cattle may appear to use less resources, and result in less methane gas on the surface," she said.
"However, one must consider all the resources that go into transporting the vegetable to a packing and processing plant, and the steps involved in transporting -- boat, plane, train or truck-- the finished product -- fresh, frozen, chopped or prewashed -- to the restaurant to end up on your plate," Sandon said.
Aside from a menu redesign, Sandon suggested there are other ways to approach eating out in an environmentally responsible manner.
"Personally, I would be more interested in knowing what a restaurant is doing to manage waste and reduce overuse of resources rather than the carbon footprint numbers on a menu," she said.
And, Sandon added, consumers already have lots of proactive options, ranging from walking to the restaurant rather than driving; choosing smaller meal portions; avoiding over-ordering, and making an effort to always bring home leftovers.
The findings appear in the May 11 issue of PLOS Climate.
There's more on sustainable eating at Harvard School of Public Health.
SOURCES: Benedikt T. Seger, PhD, postdoctoral research scientist, Department of Psychology, Julius Maximilian University, Würzburg, Germany; Lona Sandon, PhD, RDN, LD, program director and associate professor, Department of Clinical Nutrition, School of Health Professions, UT Southwestern Medical Center, Dallas; PLOS Climate, May 11, 2022