Lose a stone in time for Christmas... WITHOUT counting calories: At 48 I was overweight and exhausted but now I've transformed my health and body thanks to this simple diet. Here's how you can do the same

Sitting in the park with her grandchildren one afternoon, Becky Tucker decided to overhaul her life.

As the four of them played and ran around, Becky, then 48, simply lacked the energy to join in. It was, she says now, a wake-up call.

The risk management consultant from Poole, Dorset, had been struggling with fatigue, anxiety, mood swings and hot flushes as perimenopause took hold.

And for as long as she could remember, she had experienced intense, debilitating migraines for a week every month, linked to her menstrual cycle.

She was also significantly overweight – something she had struggled with her whole life. At more than 13 stone and with a BMI of 29 –

bordering on obese – Becky had spent the previous 25 years on various weight-loss plans. They'd work, to begin with, but then she'd pile on the pounds again when she returned to her usual diet of chocolate bars and what she calls 'beige stodge'.

It will be a familiar scenario to many in midlife – the pounds creep on until it no longer feels possible to shift them.

But three years on, it is no exaggeration to say that Becky is transformed. Indeed, as our photos show so clearly, she is almost unrecognisable. Fizzing with energy and an astonishing four stone lighter, she says she feels like a different woman.

Her enviably slender figure has shrunk by more than four dress sizes, from a 16 to an 8/10. Her near-lifelong migraines have

vanished, as have those limiting menopause symptoms.

And most importantly of all? She is now running around the park with her grandchildren, no longer stuck on a bench at the sidelines.

But what is extraordinary is that Becky achieved it – and she says this almost apologetically – 'without really trying'.

There was no restrictive diet, no calorie counting, and no pangs of hunger. Instead, Becky overhauled her diet with the help of gut health science company ZOE, co-founded by Professor Tim Spector, the scientist at the forefront of discoveries in diet and gut health and their impact on our overall health – and, research increasingly suggests, our mood.

Research by Prof Spector, an honorary consulting physician and expert in epidemiology at King's College London, suggests that simple changes to our food choices can have remarkable benefits – from helping us lose weight without going hungry to improving our mood, boosting energy and potentially protecting our brains against the effects of ageing.

And now, in an exclusive new six-week newsletter series launching on Monday 26 October, The Mail on Sunday's readers can discover how to put his research into practice – with the chance to feel happier and healthier within days, and potentially as a bonus even lose up to a stone in time for Christmas.

Based on Prof Spector’s research at ZOE, and including recipes from his new cookbook Good Mood Food, the series will guide you, step by step, through a new way of eating that could transform not just your waistline, but most importantly how you feel every day. 

You'll discover the surprisingly simple foods that nourish the trillions of bacteria living in your gut, why these microbes may hold the key to better mood and brain health, and how to feed them.

We'll show you what to put in your shopping basket – and what to leave on the shelves – and how to build delicious, filling meals.

There will be exclusive recipes, from hearty breakfasts and satisfying dinners to indulgent desserts, along with expert advice on eating to support your mood and thinking as you get older.

Halfway through, Prof Spector will make a live appearance on dailymail.com to answer readers' questions and talk about his cookbook. And as Christmas approaches he'll reveal how to enjoy your favourite festive foods without undoing all your hard work – and, crucially, how to make these changes stick for life.

Indeed, research by Prof Spector's gut health company ZOE found that 35 per cent of around 5,0000 participants lost at least 5 per cent of their body weight in just three months.

Prof Spector says: 'I'm delighted to be partnering with The Mail on Sunday and Daily Mail on this six-week series. 

'I'd like my new book, Good Mood Food, to be the readers' shortcut to eating better and feeling better every day, with recipes to lift your energy, balance your mood and feed your brain.'

Prof Spector's approach to diet has become a global phenomenon, refined through years of research involving hundreds of thousands of people.

Although more personalised recommendations are available to ZOE subscribers, anyone can follow the basic principles. 

These include eating 30 different plants a week, by making simple tweaks such as sprinkling seeds, nuts or fresh herbs over a salad or soup, or adding chopped fruit or greens to a plate. 

Prof Spector encourages people to swap meat, particularly processed meat such as sausages, bacon and salami, for plant-based proteins including beans, lentils and chickpeas, and to aim for at least 30g of fibre a day.

However, chicken, lean meat and especially oily fish can still be enjoyed as part of his approach.

Ultra-processed foods, or UPFs – industrially-produced foods lacking in nutrients and containing cosmetic additives designed to make food irresistible to eat – are discouraged. Instead, meals should be based on whole foods, with a rainbow of different-coloured plants to maximise nutrients.

'Studies have found that people who eat healthy diets, full of fruit, vegetables and whole grains, significantly improve their mood,' Prof Spector says.

'On the other hand, people who eat the most UPFs such as crisps, biscuits, sausages, sugary soft drinks, chicken nuggets and sugary cereal, have the biggest risk of mental health problems and dementia.

'When people have moderate depression, giving them a gut-friendly diet can improve or reverse symptoms in a significant proportion of them.'

Despite this, processed foods such as baked beans, Weetabix and high-fibre or seeded bread are on the menu. Fermented foods, including natural yogurt, sourdough bread, kefir, sauerkraut, kombucha and kimchi, also have a role to play, as do dark chocolate and peanut butter. Most of these feature in the cookbook.

'It's not about restriction or cutting out all processed foods,' he explains, 'it's about cutting back on the worst unhealthy ultra-processed foods and replacing them with real whole plants.'

Eating more whole foods increases fibre intake – nine in ten Britons fail to get the recommended 30g a day, which can help protect against bowel cancer, cardiovascular disease and type 2 diabetes.

All ZOE studies to date have shown improvements in mood and energy within the first two weeks in the majority of people.

High-fibre foods also make you feel fuller for longer and can stimulate the release of GLP-1, the appetite-regulating hormone mimicked by weight-loss drugs.

Becky, now 52, is proof of how powerful these changes can be – with benefits she never expected.

From eating less than 10g of fibre a day, she now regularly reaches 60g-75g. She even competes with – and often beats – Prof Spector to see how many different plants she can fit into her diet, notching up more than 75 most weeks.

As she says: 'This hasn't just changed what I eat, it has changed how I live. I'm not just lighter physically, it's mentally that a weight has come off too.

'The transformation really has been quite extraordinary, which anyone who knows me will say. And while I don't want to be one of those people who is evangelical about their diet, I will be!'

Becky had struggled with her weight since giving birth to her first child at 17. She would regularly go on Weight Watchers, lose a stone, then regain it through binge eating. As she got older, that regain became two stone.

But despite her weight struggles, it was a desire to improve her long-term health that brought her to ZOE in 2023.

Her monthly migraines were 'horrendous', and although she had started HRT it had not fully resolved her hot flushes, anxiety, poor sleep and mood swings.

She says: 'I was approaching 50 at the time, and I was thinking, "What is going to serve me well for the future?" I was also finding I wasn't participating in my grandchildren's lives in a way that was fully immersive. 

'We would go to the park and I had such little energy I would just sit on the bench and watch them.'

She started the ZOE programme in April 2023, gradually introducing more vegetables to her meals and sprinkling nuts and seeds over dishes. Crisps and milk chocolate were swapped for raspberries, nuts or very dark chocolate.

She experimented with vegetables she'd never tried, such as aubergines, bok choy and sweet potatoes, and mixed mashed butter beans into her mashed potato before eventually phasing out the potato.

She also made sure her plates were colourful, adding salad leaves and purple and red vegetables rich in polyphenols, antioxidants which can protect cells from damage.

Becky still doesn't eat breakfast, but a typical lunch now involves roasted vegetables, houmous, salad and nuts. A similar recipe is found in the cookbook called the Roasted Red Pepper and Lentil Salad.

Dinners include lentils, chickpeas or beans with vegetables and salad, or one of Prof Spector's recipes. Her favourites are aubergine parmigiana – similar to the Stuffed Aubergine Traybake found in the cookbook – and his high-protein, high-fibre cookies. A dollop of kimchi accompanies most meals.

'Within a month the migraines had gone,' Becky says. 'I put it down to a happy coincidence, but they've never come back. Within three months I felt more energised and less anxious, and the remaining menopause symptoms had gone.

'And I noticed that my weight was dropping off. It just happened naturally – and it was the icing on the cake.

'I'm running around the park with my grandchildren now, and we recently went to Disneyland Paris together, which was incredible. It was easy – I kept up with them, I had fun, and I wasn't having to think about my energy levels. I can't describe how good it feels.'

Becky has had no problem sticking to her new regime and has kept the weight off.

'What's been most powerful is that these changes feel sustainable,' she says. 'This isn't a short-term fix, it's a completely different way of understanding how food supports my body.

'I feel more in control of my health and better equipped to manage this stage of life. I can't imagine ever stopping.'

Good Mood Food by Tim Spector (Vintage £30), to be published 22 October. © Tim Spector 2025. To order a copy for £27 (offer valid to 31/10/26; UK P&P free on orders over £25) go to or call 020 3176 2937

• for Christmas party season, plus boost your mood and energy levels? Sign up to our weight-loss series with Professor Tim Spector - if you're a subscriber, it's completely FREE