Festival of light that's heavy on the calories

A Slice of Britain: This weekend, it's Diwali. Once a celebration only for Hindus, Sikhs, Buddhists, and Jains, today huge numbers of other Britons join in – and get their first taste of its dangerously delicious foods

"I've been out of bed between 3.30 and five o'clock every morning for the last 10 days to make all the food," says Ansuya Lakhani. "This is what Diwali is about; making the food your children love."

Mrs Lakhani, 65, from Barkingside in east London – or "Mum" to me – has no way of knowing who will drop round over the next couple of days to wish the family Happy Diwali and Happy New Year, but there must be enough food to offer everyone.

As if to underline the point, a neighbour and co-worker at the local charity shop calls in, and isn't allowed to leave without a bag of Indian sweets, or mithai – bite-sized cholesterol bullets of sugar, ghee and condensed milk.

In truth, like many celebrations, it requires hard work. When I was growing up, mum cooked a full Indian meal for 35 members of my family every Diwali. She has had a respite of late only because there are now too many of us to fit in one house.

All over the UK, indeed, all over the world, Diwali – the festival of lights – is celebrated at this time of year by Hindus, Sikhs, Buddhists and Jains everywhere. Small candles or diyas – made with cotton string wicks inserted into small pots filled with oil – are lit in houses, shops and temples to signify this victory of inner good over the evil within all of us.

Diwali has become integral to Anglo-Asian culture, including business owners and their families who gather in temples, halls and houses across the country this weekend to conduct the ancient ceremony called chopda pujan. New accounts books (and laptops) are opened and blessed for the start of the New Year while praying to the goddess of wealth, Lakshmi, to bring prosperity.

This is one of the ceremonies that intrigues an increasing number of people from different backgrounds and religions, according to the Swaminarayan Mandir in Neasden, north London, the largest Hindu temple in Europe, where tens of thousands of visitors – around 20 per cent of them non-Hindu – will today sample hundreds of dishes made in honour of Lord Krishna.

Leicester, where almost half of the city's population is of South Asian origin, hosts the biggest street party outside India, with crowds of 50,000 people expected to gather over the weekend for food and fireworks. The Diwali/Christmas lights were switched on two weeks ago and will be kept on until the beginning of January.

London's own big event, in Trafalgar Square, began in 2001, and was attended two weeks ago by the usual crowd of Hindus, Sikhs, Christians, Muslims and atheists, enjoying dancers, musicians and vegetarian food.

The build up to all this starts at the beginning of the 12th month of the Hindu lunar calendar – Asomas – when thousands of families across the country gather for nine nights to celebrate Navratri – the worship of strength or power – with traditional garba folk-dancing in school halls and community centres. After that there are only 20 days until Diwali to shop for saris, send Diwali cards – or texts, these days – clean the house, and start cooking.

Like most Indian women of her age, my mother has been doing this for ever. First in Uganda, until 1972, and then in England. Many of the customs have been forgotten or adapted, but Diwali is still the day women show their families just how much they care; not through presents but through food. And for many people it is the only day of the year they will go to the temple with their parents or grandparents, like those who go to church only for midnight mass on Christmas Eve.

Children – Asian, black or white – who live in multicultural areas have grown used to celebrating Diwali, Eid, Hanukkah, Guru Nanak day and Christmas. Many schools have holidays for all five religions now as teachers try to foster tolerance and friendship.

Inevitably, some traditions have changed. Most people, even my mum, now buy their mithai rather than make them. Durga Sweets in Ilford, east London, is famous for its jalebi – a deep-fried syrupy sweet – and barfi, made from condensed milk and sugar. Customers started queuing at nine o'clock yesterday morning, and the crowds continued until the shop shut 11 hours later. Inside, it is organised chaos. Three generations of the Sharma family, aged between 11 and 65, are helping. Viney Sharma, 20, a film and media student in Manchester, is manning the till: "We've been helping out every year since we were old enough to carry things," he laughs, looking at his father. "Where else would I be?"

Bombay Looks, the sari shop next door, has been doing a roaring trade as lots of girls and women show off new saris this weekend. My niece, Kaya, aged two and a half, is dressed up in her own new sari and is as excited as her grandmother. Together they perform and sing the aarti, a Hindu ritual, for the deities in the two mini temples at home. Kaya loves it, just as I did when growing up.

"Diwali is our Christmas," says my mum, wearing a sari she bought in India on her last visit. "I still look forward to the day, even though I'm getting old. Seeing my friends and family, cooking nice food for them all, I'll always love that. I'm not sure about the younger generation. It doesn't matter if they buy all the food, as long as they still get together. I hope that never stops."