It's a complicated business, eating. And one made knottier by the idea that some foods are masculine (think hamburgers and steak), while others (like yoghurt and quiche) are made for the girls. Were these ideas of gendered eating originally generated just for ad campaigns, or could the cliches point towards a deeper truth? Do men and women need different diets? How many of our views on what constitutes "women's food" come from how we're brought up, and how many are tied to something genetic? If men are from meat, are women from cupcake?
Grant Achatz, molecular gastronomist and winner of the James Beard Foundation's award for best chef in the United States in 2008, snorts at the idea of gendered eating.
"What is a masculine presentation? Is it a giant chunk of roasted meat? What makes that manly - the caveman connotation?" he says.
"Dig into periods of time or age, geographical location, ethnicity and urban versus rural areas and you will find a separation in cooking familiarity and perhaps skill. But that has more to do with society's control over gender in general than the genetic makeup of people."
Though many of us agree with Achatz in theory, we also tend to stick to our gendered diets. In the Observer canteen, I linger by the serving hatches and watch what people eat. Out of 20 diners choosing the steak and mushroom pie over the vegetable quiche, 18 are men. Out of 10 people lingering by the dessert bar - today's option is a coagulated fruit tart, warming orangely under a hot lamp - seven are women.
I admit, the science is not 100 per cent flawless, but my observations suggest that, given a choice, women don't eat pie, and men don't eat pudding. Why?
In 1982, Bruce Feirstein published the bestselling "guidebook to all that is truly masculine", Real Men Don't Eat Quiche.
"Think about it," he wrote: "Could John Wayne ever have taken Normandy, Iwo Jima, Korea, the Gulf of Tonkin, and the entire Wild West on a diet of quiche and salad?"
I ask a man in the canteen what stopped him from going for the quiche today, and he pauses, fork tapping his chin to denote thoughtfulness. "I need meat," he concludes.
"And I like pie." And why aren't you having dessert? "Pudding's a bit, how can I put it? A bit ..." And then he flutters his hands like a dying bird, and purses his lips, prettily.
Then there's chocolate. Traditionally it has been thought of as primarily for children but secretly, for women, when we're not sensually crumbling a Flake, enjoying some feminine "me-time", we're heartbroken in pyjamas, spooning chocolate icecream into our communal mouths.
We're chocoholics. We crave cocoa like others need glue. Is this a scientific truth? In the 1990s, Yale University professor Linda Bartoshuk devised a bitterness test. She classified the American population into super tasters, medium tasters and non-tasters.
Super tasters, she said, live in a "neon world" of flavours; non-tasters in a "pastel world". She found a much higher proportion of women were super tasters, responding more to bitterness than men.
Does it follow then, if women taste a bitterness that men miss, that women indeed have a "sweeter tooth"? Anecdotal evidence suggests that women like chocolate more than men - in April, a British study of 2000 showed a third of women dream about chocolate during the day, compared with only 11 per cent of men. Some researchers say this is because chocolate releases dopamine (a substance which peaks during orgasm) in the female brain. It's even been suggested that when women eat chocolate it affects activity in the amygdala, a part of the brain which regulates sexual desire.
Psychologists see it more simply, explaining that chocolate's appeal to women is in its status as a forbidden pleasure to those on diets. The chocolate industry is dominated by brands aimed at women. Jill McCall, a brand manager at Cadbury, is careful to point out the difference between the indulgent, feminine bars (Flake) and the masculine "hunger bars" (Snickers), which are nut-filled and huge and fill you up rather than provide a girlish "treat", thereby creating markets within markets.
Chocolate is one of the things most associated with a female diet but it's when we think about savoury foods that we're able to separate the advertising from the eating. Yale-Griffin Prevention Research centre director David Katz believes our gendered diet can be explained by evolution. As cavemen, he suggests, men were hunters, relying on protein to build muscles, and seeing meat as a reward, while women were gatherers of fruit and vegetables. "Men and women have differences in physiology," he says, "which might have to do with [early] access to different kinds of food." Differing access to foods in prehistoric times, he says, led to gendered patterns of eating today.
Yvonne Bishop-Weston, a Harley St nutritionist, agrees that men are drawn to fats, meats and proteins, but says it's not down to an "evolutionary need - it's down to socialisation. Boys are encouraged to have big appetites from a very young age. It appears possible that there are fat receptors in the brain, so everybody craves it and because of our greater hormone cascade, women actually crave it more."
Bishop-Weston sees gender differences less in how people eat, more in how they think about their diets.
"Women have more emotional attachments to food - due to media pressure they attach guilt to carbs and saturated fats, and often feel a responsibility to eat healthily in a way that men don't," she says.
"Interestingly, though, I see a trend towards 'effort' that spans and unites the sexes. People are becoming more receptive to things that take longer. People are looking for an identity with their food. People are buying breadmakers. As everybody's lives are getting more stressful we feel worse, and we need more nutrients. So both men and women are getting scared into eating well."
Another food trend that comes dipped in gender is the so-called "cupcake revolution".
While the "fairy cake", as we used to call these palm-sized party snacks, summons images of angry four-year-olds pushing Smarties up their nose, the "cupcake" brings fragrant visions of a pre-feminist 1950s housewife, baking for pleasure. Alongside their appearance on Sex and the City, where they were fetishised to within an inch of their soon-stale little lives, cupcakes last year became fashionable around the world, with one British fan (who, dressed as her alter ego Cherry Bakewell, hosts cupcake parties) describing them as a "real symbol of femininity, a camp symbol of a bygone era". Here is the baked and ironic response, cupcake lovers say, to post-feminist culture. Similarly, Esquire magazine's Eat Like A Man blog celebrates "foods that men love and ... ways that men eat", embracing the idea of gendered eating as a way of marking out their masculinity in grilled meat.
Jamie Robertson, a British gay television producer, says sexuality has little to do with diet, "though the gay stereotype is often considered to be more domesticated than the heterosexual man. Personally, I find most gay guys no more comfortable in a kitchen than their straight mates but I'd like to think, on average, our diets are a bit more adventurous and varied, opting for the [ready meal] tuna nicoise rather than chicken pasta salad. We are more 'experimental' by nature, curious to see what they're eating on the other side of the fence - after all, that's what got us in on this gay circus in the first place."
"It's important to remember that marketing is not a conspiracy," says David Bell, author of Consuming Geographies: We Are Where We Eat, and senior lecturer in critical human geography at the University of Leeds.
"When advertising works successfully it confirms the stories we already believe - think of the Oxo family - or it shakes us up, so we know the story's been subverted," Dr Bell says.
Bell, whose work on food consumption concentrates on how we use food to work out who we are, says: "'Nature' isn't natural. It's cultural. It's a story we tell to help us understand the world, and it's powerfully appealing in our post-Darwinian, secular culture. We need ways to explain the world and who we are, and nature, via science, gives us that."
Tastes change over time, he says. Partly due to the availability of foods, and partly due to the "tastemakers" of a time, the people who guide the rest of us through ideas of class, culture, and indeed gender. But whatever the historical period, the diets men and women choose tell us a story about gender at the time. For example, the idea that men need more calories than women, or can drink more alcohol. "These are cultural stories about gender. Partly to do with the gendered division of labour, partly to do with the construction of the gendered body."
And these stories change and adapt over time, too. He reels off current ideas about what men and women eat, but says he's suspicious of the ways used to explain them.
"We can explain different gendered eating habits and tastes via an evolutionary story about what men and women 'naturally' do and 'naturally' like," he says, where every choice we make leads back to the need to propagate the species, as Yale's David Katz proposed.
Man is the hunter, therefore the breadwinner, the meat eater, the firemaker, the king of barbecues. Woman is the gatherer of vegetables, the salad eater, the nurturer, the homemaker, the cupcake-maker. "And clearly we rely on a set of gendered understandings here, but when we grasp around for reasons, this evolutionary story is all we grab on to. Gender, like nature itself, isn't 'natural', it's something we 'do'. And we do it all the time, which means we do it when we eat. We learn our tastes, and part of that learning is gendered."
Women aren't disposed to sweeter tastes or men to sourer, Bell says - the fact that we think they are is an element of our cultural story. "The story we tell to understand the world and our place in it. We're living in a culturally rich time, and are more than able to divide food into categories, including one for 'food that people like me eat'."
So, men don't eat steak because they are men, men eat steak to show they are men. Women aren't hard-wired to crave dessert - we've learned that women crave dessert, so we follow, mouths open.
"It's comforting," Bell says. "It's reassuring when we make sense of things."
Have you observed gendered eating? What foods do you think are masculine and which are more feminine?