Somerset butter from Scotland, Welsh lamb from New Zealand and West Country fish fillets filleted in China: just some of the false "local food" claims misleading consumers who believed they were eating local produce highlighted in a Local Government Regulation investigation earlier this year. Almost one in five claims about local food was found to be false.
At a time when diners are more empowered than ever and expecting businesses to be on best behaviour, it makes no sense to try and hoodwink them.
Greenwash just doesn't wash with discerning diners. Trumpeting your legitimate green credentials is to be recommended. Trying to kid your customers that you're more sustainable than you really are may pay in the short term - but long term will be very damaging to business. And, at the risk of sounding precious, it will lay waste to the credibility of the whole sustainability movement. As Warren Buffett said: "It takes 20 years to build a reputation and five minutes to ruin it."
In fact, restaurants risk more than their reputation. Outlets which are not able to substantiate the descriptions for their dishes have been warned they face prosecution if they do not correct any misleading claims and they could face an unlimited fine and two years in prison.
There are some mitigating factors. For instance, the word "local" has attracted many definitions, making it genuinely confusing for chefs and diners alike. The Sustainable Restaurant Association's (SRA) preferred one is that produce must be sourced within 50 miles, or 100 from London, to be local.
Over and above keeping on the right side of the local Trading Standards department, restaurants should look to set their own standard - well beyond the requirements of the law.
There are a number of SRA-member restaurants making a virtue of transparency - on their menus and websites - not just about the provenance of their produce but also in important matters like their policy on tips and nutritional content, recognising the Department of Health's Responsibility Deal.
Feng Sushi - a small group of Japanese restaurants - treats its customers like grown-ups. That means the information is available for those who want it, but diners don't feel like they are having it thrust down their throats.
Owner Silla Bjerrum says: "Our customers are very interested in the nutritional content of their food, so we publish detailed information on our website and we are planning to publish leaflets that will be available in the restaurants. But it's a fine balance. We want to be transparent and for people to be aware of the nutritional value, but not over and above the flavour and quality of the food. We also don't want to preach to our customers."
Feng Sushi recently started producing a newsletter. So every six weeks it is communicating with its customers about seasonal dishes, its suppliers and its commitment to sustainability.
"We've had a really positive response to the newsletter and we do our best to respond positively to any customer criticism. I try and deal with any complaint personally," Bjerrum adds.
As well as not making false claims, restaurants should be sure to communicate clearly the good things they are doing.
Despite having a fair tips policy in all her Feng Sushi restaurants, Bjerrum doesn't currently make this clear to customers - something she's about to put right. Like all sustainable things - there's always more that can be done.
Five ways to ensure you market responsibly
1 Assess your suppliers' credentials before making claims about them
2 Train your staff about sustainability so they can answer customer questions
3 Communicate with your customers about what you and your suppliers are doing via a regular newsletter
4 Ensure your menus and website contain clear, honest and transparent information, avoiding lazy use of buzz words like local and seasonal
5 Get star-rated by the Sustainable Restaurant Association - the best way to communicate your sustainability to customer
The Sustainable Restaurant Association is a not-for-profit organisation helping restaurants become more sustainable