"I had 'no more excuses' tattooed on my right arm when I was in Rio de Janeiro, because I needed it," says Massimo Bottura. You wouldn't think one of the world's most successful chefs – with three Michelin stars and a restaurant that's been voted one of the five best in the world for the past five years – would need such a strong reminder to put their mind to anything. But, when it comes to fighting food waste, Bottura believes you can't be reminded enough.

When he speaks about his Food For Soul project, he bubbles over with passion – talking at mile-a-minute pace; hopping from one theme to another; barely breaking for pause. The non-profit organisation came into being after he ran an initial pop-up 'refettorio' during Milan's Expo 2015, where food waste was used to create nutritious meals for those in need.

The pop-up went on to become permanent, setting up in Milan's Greco quarter, and was so successful that the mayor of Rio de Janeiro enlisted Bottura to do the same thing in Brazil ahead of the Olympics.

There are now refettorios in Bologna, Milan and London, where it's found a home in Kensington – which, despite its reputation for wealth, is home to some of the most deprived pockets in the UK, as the fallout from the Grenfell Tower fire has highlighted.

More than 50 well-known British chefs joined Bottura for the launch, and the kitchen is now run by a team of volunteers that work with food waste charity The Felix Project. The organisation collects surplus food from supermarkets, wholesalers and other food suppliers and then delivers that produce to charities across London that provide meals for the elderly, the homeless, refugees, and those with mental health problems

As you might expect given its provenance, Food For Soul has been hugely successful, saving more than 25 tonnes of surplus food from going to waste so far – and with more refettorios in the pipeline, it's well on its way to doing more.

Here, Bottura tells us why London was the right place to set up a soup kitchen, why this project is about more than food, and why making a difference actually matters.

What was the inspiration behind setting up Food for Soul?

It started [with a pop-up] during the first Expo in Milan in 2015, and the theme was 'Feeding The Planet, Energy For Life'. I looked at the statistics – despite world hunger, 33% of the world's food production is wasted every year. It seemed obvious to me: we don't need more production, we don't need more food. We need to waste less, and how can we do that?

I wanted to show the world that the things they think are waste are really just ordinary ingredients. If, with ordinary ingredients like that, we can show the world that we can create amazing recipes, that's what really makes the difference. Who [is in the right position to] give the world that example? The best, most influential chef in the world.

The organisers of the event trusted me because they know I'm crazy about quality, and that I have a lot of respect from other chefs and my colleagues, and everyone [I asked to help] said yes. All the phone calls were over after 45 minutes – they all said yes straight away. The minister of agriculture in Italy said the Refettorio was the most significant project at the Expo.

Food For Soul came about after we had just closed the Milan Refettorio pop-up. At 6am, I had a WhatsApp from the mayor of Rio and from David Hertz of [Brazilian social gastronomy initiative] Gastromotiva, saying they wanted to do a project, too. And I thought, why not? Lara, my wife, said, "What are you doing? Are you crazy?" I said, "No, Lara. I think it's a great opportunity." At a time when the mayor of Rio was closing soup kitchens, we opened a soup kitchen. You build walls and we'll break them.

We don't need more production, We need to waste less. So How do we do that?

Why did you bring the Refettorio project to London?

London is at a key moment with Brexit and it's the perfect place to do it because of the culture here – you can understand my project very well, and it was easy to do here. Easier than Milan and Rio.

British chefs responded in such a deep and enthusiastic way, it was unbelievable. I didn't choose the place in Kensington – it chose me. We were exploring the area and we went to visit The Felix Project, an amazing charity in London that rescues food that would otherwise disappear. I saw the building and said, "This is it." I had that vision.

How does the project choose who is invited in to eat?

In London, it's St Cuthbert's [a West London-based community centre]. They run it day-to-day and they select the people because they have a lot of requests. In Milan, there was Caritas, the Catholic church organisation. In Rio de Janeiro it was the Gastromotiva guys with a few local communities.

Who eats there depends on the place. In Milan, at that time, it was 50% of homeless and 50% refugees because we have a lot of people there. In Rio it was the people who live on the street. There are 2.5 million people who live on the street there, so it was strange and difficult. In London, it's mostly homeless people who live in the park. In Bologna, it's all families.

But the most shocking one was Modena, my hometown. Some of the guests were people I've known for 30 years, people who live in downtown Modena and don't have anything to eat because of the economic crisis or the family splitting up.

Why is it important for you to make the space aspirational and include art and design elements?

It's such an amazing space. We didn't need to put a lot of art in because we had these incredible gothic-style windows that are already pieces of art themselves, but we do have some beautiful neon handwriting.

London is at a key moment. I knew people here would understand this project

The art, design and architecture are as key to the project as the best chefs. People don't live from just bread alone, they live for something much deeper, so that's why I really care about this. For example, when we opened in London, there was a 92-year-old lady who asked for a microphone. She was so emotional and moved by what was happening that she talked with everybody, telling them, "I'm 92 years old and this is the first time in my life that I feel a sense of community. I just want to say thank you, I can die very happy and I can spend the last years of my life close with the people I know in an amazing space." This is exactly the reason we wanted to create such a beautiful setting.

How many people have been fed at Refettorio Felix so far? Has it made a genuine difference in the community?

Every day, between up to 90 people are fed there. But it's not just about meal times. There's an area where you can use the computer and connect to the internet. At 10am, there's tea.

The local community is so happy. It's one of the key points of all of our projects. In the beginning they don't get it. They think just migrants or refugees or poor people are coming and they're going to create problems.

In Milan, the Refettorio is such a beautiful project, with the architecture, the art and outside there's an amazing door by Mimmo Paladino. There's beautiful neon writing that I also have a tattoo of on my right arm – 'no more excuses' – which I had done in Rio.

But the whole neighbourhood and community of the Greco [one of the poorest areas of the city, and where the first Refettorio is based] has changed. They are building new bars and restaurants. It's crazy, but it's actually happening. And the whole community is involved, just like in London. There are so many volunteers. There are so many people who want to help out. It's incredible.

At the end of the day, this isn't a charity project, it's an inclusive, cultural project with a focus on fighting food waste – and the more we talk about it, the better.

Learn more: foodforsoul.itrefettoriofelix.com