What, if anything, would persuade you to swap a warm shepherd’s pie or a spicy curry for a cold, crisp salad? And not just for one night, but for the rest of your life: you would never tuck into a plate of cooked food again.
Now the nights are drawing in, it’s not the most tempting proposal.
But what if the results were a crease-free forehead, cheeks as rosy as a Braeburn apple, twinkly eyes and a tauter tummy?
On top of that, it would have you brimming with energy and put the spark back into your sex life.
Well, this is what eating nothing but raw food does for you — or so says Susan Reynolds.
She hasn’t eaten anything hot for seven years, and is regularly thought to be ten years younger than her 29 years.
‘It’s not all about looks,’ she hastens to tell me, despite her striking — make-up-free — prettiness. ‘I choose to live like this because it makes me feel great.
‘When you eat heavy comfort dishes, you sink into what I call a “food coma”. You eat mashed potato, you feel like a mashed potato.
‘But after consuming raw food you feel much more energised. You want to do things.
‘Imagine the impact on your sex life if, rather than slumping on the couch, you feel revitalized after dinner. You’re like, “let’s go!”’
A cheeky glint enlivens Susan’s fresh-faced air of innocence.
For while this ‘raw-foodist’ survives on a pretty spartan diet, she’s not the dour puritan you might expect; she understands the lure of dietary vices.
‘It’s not about denying yourself things,’ she insists.
‘You can still eat cake and chocolate. You just make raw versions of both.’
Raw chocolate — who knew? It’s made from ground rather than roasted cacao (the botanical term for chocolate) and coconut milk is added instead of cow’s milk.
Raw cakes are made in a similar way to cheesecakes, with a base created from processed almonds, dates and coconut oil, set in the fridge, while the topping is sweetened coconut milk.
And although Susan no longer drinks alcohol (apart from the very occasional whisky with her dad), she says she’s discovered a chocolate tipple that’s every bit as stimulating.
She explains: ‘I make a special raw chocolate drink by blending it with chilli and a superfood called maca, which is actually an aphrodisiac.
‘It makes you feel like you want to go out and party.’
The trend towards so-called ‘raw-foodism’ has been gaining ground in recent years, the rule being you can’t consume anything cooked at more than 40c (104f), because above that temperature food loses much of its nutritional value.
But while supporters claim that eating uncooked food can help you lose weight and fight chronic diseases, experts have raised concerns that they are putting their health at risk by cutting out vital food groups.
Susan says: ‘The two main questions I get asked are, “Don’t you miss comfort food?” and, “What about protein?”’ She has answers for both: she says she gains comfort from other things like ‘beautiful linen sheets or listening to music’ and adequate protein from leafy greens such as spinach and rocket.
‘In fact I often have my blood taken and everything’s fine. I’m the healthiest I’ve ever been.’
Not that Susan has always been so virtuous. The youngest of three girls, she was born to a businessman father and artist mother in Edinburgh before the family moved to Manchester when she was five.
‘We ate the average British diet,’ she says. ‘Cereal for breakfast, meat and veg for dinner and snacks such as crisps and sweets.’
But when she reached her early teens, Susan’s mother fell ill with ME. ‘It was really difficult for her,’ she says. ‘She had to go on a sugar-free diet for a while — maybe two years — and that really helped.
‘I guess her experience made me think more about my health.’
Susan started going to the gym every day and during her late teens and early 20s she began experimenting with different eating plans: going gluten-free, and trying out veganism and the Atkins diet.
It wasn’t a question of wanting to lose weight — at 5ft 11in tall, she weighed a trim 10st. But she was suffering from symptoms similar to those experienced by people with irritable bowel syndrome (IBS) and was looking for a way to cure them.
When Susan was 22, she first started cutting out cooked food altogether — in part as a result of a broken heart.
‘I’d just split up with my on-off boyfriend from university,’ she says. ‘Mum took me out to lunch at this raw food cafe to cheer me up.
‘I noticed the owner, who was in his 30s, and thought he looked incredible; so young.’
That night she did some research online and decided to try it.
She says the benefits kicked in immediately: she didn’t get that post-hot-meal slump and her digestive problems cleared up.
She started going to the cafe every day for a smoothie on her way to work, and would go on to have a five-year relationship with the owner — he taught her how to make the diet work.
So can a raw food diet really be a good idea?
Many raw foodies believe that the diet makes the body more alkaline, allowing it to better fight off toxins. Others claim that heating food causes the vitamins in it to leach out, and raises the levels of free radicals in the food, which are linked to ageing and chronic disease.
They also claim it helps you to keep a healthy weight. A U.S. study published in 2005 found that raw food volunteers had a lighter body weight, lower Body Mass Index and less body fat than those who ate a typical diet.
Although Susan didn’t go on the diet to lose weight, she has lost a stone over the years, taking her down to 9st.
‘There are other raw foodies I’ve met who have lost half their body weight,’ she says.
Not that it’s easy — it does require a change of lifestyle to become ‘100 per cent raw’. ‘You can only shop in the first two aisles of the supermarket, for a start,’ she says.
If, just like Susan does, you also insist on only consuming organic produce, this lifestyle can be costly too. ‘Yesterday I bought all my food for that day from Waitrose and it came to £20,’ she says.
In total, Susan believes she spends more than £7,000 a year on food.
But it’s not just the financial cost of the raw food diet that worries dietitians such as Helen Bond. She says going ‘raw’ could ultimately be bad for health — and leave you feeling exhausted.
‘The danger of this diet arises from all the nutrients you’re missing out on, for example wholegrains which you get from rice, potatoes and pasta, all of which need to be cooked to be enjoyed.
‘These are important for fibre and energy and keeping your blood sugar levels low.’
Then there’s protein, which is needed for building healthy bones and muscles. Bond, who is a spokesperson for the British Dietetic Association, questions Susan’s claim that it’s possible to get sufficient levels of protein from leafy greens.
‘There’s very little protein in greens, so you’d have to eat an awful lot to get your Can eating only raw food really spice up your sex life and make you look 10 years younger?. I suppose you can get it from nuts and seeds but the best sources of high quality protein really are eggs and lean meat.
‘I’d also be concerned about getting enough iron — you can get some from vegetables, but not haem iron, the type of iron that helps to make sure your red blood cells are moving round the body.’
She admits that a raw food diet would probably help you lose weight, but more because your repertoire of available foods is so limited than because of any magical quality. And while some vitamins are lost from vegetables when we heat them, this is not true for all foods: betacarotene, the nutrient found in butternut squash, tomatoes and carrots, is much more easily absorbed into the body when it’s been cooked.
‘I do think we should incorporate raw food into a balanced diet, but people take it too far and the disadvantages start to outweigh the benefits.’
But Susan Reynolds’s commitment to the diet is unwavering. She sticks to a litre of green juice made from lettuce and herbs for breakfast, snacks on raw chocolate and berries during the day and has a large salad or soup for dinner.
And she insists that she has continued to enjoy the myriad benefits of the diet: ‘Mental clarity, positivity, health and radiance.’
It’s the latter that has inspired the most interest from others.
‘I don’t look in the mirror and think: “I look so young!”’ she says. ‘But when I tell people my age they often say: “29 — really?”’
Sure enough, these attributes are in evidence upon first meeting. And despite her modesty, surreptitious glances at her forehead don’t reveal a single line: pretty good going for someone touching 30, whatever dissenters might say.
Compare her to a photograph of her 22-year-old self — taken before she started the raw food diet — and if anything she now looks more sprightly, more youthful. So much so she has recently acquired a 22-year-old boyfriend, Liam.
These days she and a chef friend have set up Twist and Sprout, ‘raw food and yoga’ retreats, as a way of winning others round to their cause. Certainly, you couldn’t find a better advert than Susan.
But whether raw food is the key to eternal youth or not, what would you rather reach for after a long chilly day: a bowl of cold soup or a piping-hot pie?