Our research shows that some high street chains are being more proactive about improving sustainability, and helping customers make sustainable choices, than others.
We asked 28 big UK restaurant chains what they are doing to be more sustainable, and compared the results. Wahaca topped our table with the highest eco-credentials, followed by Nando’s, Frankie & Benny’s, Young's & Co Pubs, Pret a Manger and Wagamama.
Greggs and KFC came last in our rankings, partly because they didn’t share key data with us. Some companies refused to share any information at all.
See the full rankings below.
Eat well, live better, stay healthy –Most and least sustainable UK restaurant chains
Our eco-restaurant rankings are based on information the restaurants shared with us when asked, and include rankings for resources and emissions, sourcing policies, waste and plastic use, transparency and targets.
Wahaca came top overall with a score of 84%, while Greggs and KFC came joint last with a score of 38%, partly because they didn't share some key information with us:
Table notesabWhich? Restaurant Eco-Providers
These are our top-rated picks:
Overall score 84%
Mexican food chain Wahaca came top of our table.
It serves mostly small plates for sharing, and its restaurants are mostly in London, with other branches in Brighton, Edinburgh and Cardiff.
Wahaca prides itself on being sustainable and scored highest on sourcing policies (along with Nando's), as well as transparency and customer choice.
It sources free-range chicken, pork and eggs and has made a conscious effort to reduce the amount of beef it offers on the menu, with only one beef dish available. All of its fish is MSC-certified and it sources palm oil, soya, tea, coffee and sugar sustainably.
It champions plant-based eating, and 60% of its menu is vegetarian. It's also the only restaurant in our survey that lists the carbon emissions for each of the dishes on its menu.
Overall score 81%
Nando's is best known for its peri-peri chicken and has 478 restaurants in the UK and Ireland.
It scored 100% for its waste and plastics policies and creates a relatively low level of food waste for a business of its size. None is sent to landfill.
Energy and water use are also relatively low and Nando's gets the highest score in this section (alongside Burger King). 100% of its electricity and gas used in England, Scotland and Wales is from renewable sources.
Nando's also tops our sourcing policy section alongside Wahaca.
Compared to other chains in our survey, the menu at Nando's is relatively streamlined so it can focus on sourcing policies for its ingredients. It has robust policies for palm oil (it's minimising its use), soya (which it uses a lot in chicken feed), tea, coffee, sugar and chocolate.
All Nando's staff receive sustainability training.
Overall score 75%
Frankie & Benny's is an Italian-American-style chain with more than 50 branches in England, Scotland and Wales. It offers pizzas, pastas, salads, burgers and hotdogs.
Almost a third of its menu is vegetarian or vegan. The chain uses sustainable cleaning products and has a sustainable policy for restaurant fit-outs.
Until September 2023, Frankie & Benny's was part of The Restaurant Group, which also owns Wagamama. The group has reduced its food waste by studying its most-wasted items and ingredients on its menu and removing or reducing these.
It has ambitious reduction targets for emissions, water use and food waste and avoids using single-use plastics.
Frankie & Benny's is now owned by the same parent group as Bella Italia, which didn't do as well in our survey, so things may change in the future.
Overall score 74%
Young's is a pub chain predominantly in the south east and south west of England.
Its pubs serve higher -welfare and sustainable ingredients – the pork is RSPCA Assured, steaks are West Country PGI (Protected Geographical Indication, which protects local and traditional production) and beef is sourced from ex-dairy cattle.
Haddock in fish and chips is MSC-certified, and eggs are free range, and the menu is seasonal so ingredients can be sourced from the UK where possible.
The company doesn't use any palm oil, and its tea, coffee, sugar and chocolate are Fairtrade or Rainforest Alliance certified.
It has a responsible refurbishment policy to pub fit-outs and a recycling and waste initiation across all premises that ensures no waste goes to landfill.
One innovative example is its cooking oil, which is recycled for biodiesel – to date, the brand says it's recycled 334,325 litres.
As the pubs don't do takeaways, packaging is kept to a minimum and it scores well in the waste and plastics section of our analysis.
Since April 2021, 100% of its electricity is from renewable sources.
Overall score 73%
Pret, the sandwich chain, is the only 'takeaway' in the list to make it as an Eco Provider. It has more than 400 outlets in England, Wales and Scotland.
The chain sources 72% of the ingredients for its sandwiches, salads and other dishes from the UK.
It has made a conscious decision to limit beef on its menu for environmental reasons – only two of its 176 menu items are beef-based.
Most of its pork items are made using higher-welfare outdoor-bred pork, and the one that isn't is under review.
All of the eggs used are free range, the milk is organic, and fish is sustainably sourced.
Pret's plant milks, tea, coffee, matcha and hot chocolate powder are all organic, and more than 50% of excess food is donated to charities or food-sharing platforms.
Overall score 72%
Wagamama scores well across all categories in our survey.
The chain's takeaway packaging is now fully recyclable and it uses eco cleaning products in its restaurants.
Uniforms are made from organic materials that are grown without using pesticides, and it buys sustainably grown soy, palm oil, tea, coffee and sugar.
Wagamama has more than 150 restaurants across England, Scotland and Wales.
, as rated by customersLow scorers and the restaurants that didn’t respond
Greggs and KFC sit at the bottom of our eco table, with their scores being impacted by the omission of key data.
Greggs' scores were average but it didn't share information on its water usage, food waste and non-food waste sent to landfill.
Greggs said: 'The Greggs Pledge is our commitment to making the world a better place by 2025 focused around three key areas: building stronger, healthier communities, making the planet safer and becoming a better business. We continue to make good progress against our ambitious Pledge targets which has not been reflected in this report as we do not yet publish all the specific data requested.'
Similarly, KFC scored well for emissions but didn't share information on electricity or water consumption, renewable energy, food waste and landfill. This meant that it scored 0% in the waste and plastics section.
KFC told us: 'KFC has pledged to be a Net Zero business by 2040 or sooner, 10 years ahead of government targets. We are passionate about embedding sustainability across all areas of our business and are working with a range of experts to ensure we get this journey right. We believe this report does not fully reflect our position and ongoing commitment to operating responsibly'.
Some restaurants refused to share information, or ignored our information requests entirely. These were:
Five GuysHungry HorsePizza ExpressSubwayTGI FridaysYo! SushiBig chain restaurants make millions in revenue each year and have a huge environmental impact. They have a responsibility to reduce this, and their customers expect it.
In a Which? survey of 1,168 members in December 2023, 44% of respondents told us they wanted restaurants to be proactive in being more sustainable, and 27% would like to see restaurants provide sustainability information on menus.
Why where you choose to eat out matters
49% of Which? survey respondents told us they consider the environmental impact of the food they eat. But there's a difference in attitudes when eating out and at home.
85% think about avoiding or reducing food waste when they eat at home, compared to 30% when eating out.
This isn't surprising – for most people, eating out is an occasional treat and they want to enjoy themselves without worrying too much about what they should and shouldn't eat.
But our research shows that where people eat matters, and some restaurants are being more responsible about their environmental impact than others.
Restaurants can help create change
The best restaurants empower customers to choose options that have less impact, and show that eco-friendly choices can still be tasty.
Wahaca told us it's seen the real-life impact of doing this. The brand labels dishes as low, medium or high carbon impact on its menus.
It told us: 'In research carried out with Imperial College, 66% of respondents said that carbon labelling had encouraged them to choose a lower carbon option'.
Mitchells & Butlers, the group that owns Harvester and Toby Carvery, told us it had trialled labelling sustainable choices on menus in Harvester but stopped because it hadn't changed customer behaviour. A similar trial at All Bar One, one of its other brands, has been much more successful and has been rolled out widely.
While some audiences may be less receptive than others, it's clear that more information has the power to influence consumer choices.
– we surveyed gym goers to find the best chains, and best cheaper optionsHow we assessed restaurant sustainability
In July 2023 we asked 28 of the biggest UK restaurant chains what they were doing to be more sustainable.
Our eco-restaurant rankings are based on information the restaurants shared with us on their last complete year's reporting (usually 2022). The overall score is based on:
40% Resources and emissions20% Sourcing policies20% Waste and plastics 15% Transparency and customer choice5% TargetsSome scores were awarded relative to the size of the company.
By law, companies must report on their Scope 1 and 2 emissions. These are emissions from the energy used in running a business and in producing that energy.
A company's supply chains also produce emissions (known as Scope 3 emissions) which include emissions from the production and processing of ingredients, transportation and waste disposal.
In hospitality, these usually account for at least 90% of a company's carbon footprint. For quick-service restaurants it's even higher: 99%.
Companies don't have to report their Scope 3 emissions (yet) so these weren't included in our resources and emissions analysis. As a proxy for supply chain sustainability we looked at sourcing policies for the food items that have the greatest environmental impact.
While there is more work to be done, and some restaurants could improve their scores by being more transparent, our eco-providers show that positive changes can be made and have an impact.
For monthly tips on positive changes you can make for the planet and your pocket, sign up to oursource https://www.which.co.uk/news/article/most-sustainable-uk-restaurant-chains-revealed-aVio22t7pseq