Forget bio-yoghurt and virtually-fat-free-everything, more and more of us are eating just what we like - and that means Big Food.
Belgo restaurant in London's Covent Garden is highly trendy. Even on a Monday evening, the quietest in the week, this fashionably minimalist underground brick-lined cellar is packed to the gunwales by half past nine. The place seats 450, and all of them, sitting at the bare wooden tables, are eating and eating and eating.

At one table, three elegant women are gossiping enthusiastically. They are also troughing enthusiastically, devouring enormous platters of moules, with bread and bowls of frites and great gobs of mayonnaise on the side. The waiter brings hot towels to wipe away the glistening traces of gluttony, and they proceed to huge dishes of ice-cream swimming in frilly whipped cream, and buckets of cappuccino. Dainty eating this is not. Across the aisle, a young woman is getting to grips with half a chicken, while the man with her wraps himself round wild boar sausages and a mound of stoemp (Belgian bubble and squeak). Everyone is having a great time, talking at the tops of their voices, sinking a succession of beers, and stuffing themselves silly.

It seems that going out, eating lots and (optional extra) making lots of noise is (shock!) considered a fun evening. Belgo is currently turning out 2,000 meals a day, which is a lot of kilo portions of moules and spit- roasted poules. And they are far from alone in abandoning the idea of serving up three cubic inches of salmon in a dribble of sauce glacee aux epinards and pretending it's a main course. From the poshest and trendiest restaurants to the most workaday eateries in the land, big nosh is on the menu.

Pizzaland and Pizza Hut have long had "all-you-can-eat" buffet offers (though this generosity can backfire - a manageress at Pizza Hut in Middlesborough ejected three students who cleaned her out of pizza and pasta, much to their disgruntlement - they had planned to go on to the unlimited ice- cream deal). At Mezzo, the ne plus ultra of chic eating, the menu is likely to include pork belly, rib of beef, rump of lamb and boiled salted ox cheek with carrots among the more exotic choices.

TGI Friday takes the American route, with huge portions of steak and salad and creamy cocktails served in buckets on stems. A proud spokesman points out that their wine glasses hold a third of a bottle, not the paltry fifth one might expect in lesser establishments. One of their desserts, the Friday's Outrageous, has a whole bar of milk chocolate poked in the top. Yesterday they launched a new brunch menu, which includes nine-inch waffles slathered with cream, and tenderloin steak Benedict served on muffins with egg, hollandaise sauce and fries. It's surprising people can actually stagger to their feet afterwards.

In the meantime, sandwich fillings grow ever more extravagant. Finding an Emmental-Gruyere combo with extra ham and spicy onion marmalade on walnut ciabatta is simple compared to digging out a simple Cheddar on white. The naff Eighties cut-and-come-again carvery has given way to a much more up-to-the-minute and elegant way of allowing diners to eat more without guilt - the prix fixe menu. If you've paid pounds 20 for three courses, there's no way you aren't going to eat the pudding. In fact you feel it's somehow a duty.

Even official health advice wants us to eat more, not less - though of the right foods, of course. Anyone trying to stick to the Government's five portions of fruit and veg a day will know that this is a fair bushel to chomp. Similarly, getting one's fibre intake up to recommended levels involves a quite frightening baked bean quota.

All this is likely to have an effect not only on the waistline but on the psyche. Happy eaters abound. "I love eating, not just for hunger's sake, but just for the sheer pleasure of it," says Claire, 26. "No one could call me skinny, but I eat what I want and I don't worry about it. I've taken to buying my trousers at Gap for men, they are made for real shapes, not all tight and clingy and tapered like women's clothes. And they are obviously geared up for it in the shops. I told the assistant I was a generous size 12 and she said, 'oh, in that case you need a 32'. She was right."

Anyway, she certainly isn't fat, as her boyfriend, Adam, points out. "She is just normal. I like it when we go out for a lovely meal and we both enjoy it. I love food myself. My mum's a fantastic cook and I'm used to eating until the food's gone - it's the environment I grew up in."

As long as you don't take it as a licence to gorge on pork pies and McDonald's every day, eating what you want can do you good. "I gave up dieting and pretty quickly put on 10 pounds," says Janet, 29. "But people all told me how well I was looking. I've got back the nice bosom I starved away, I feel healthier and calmer, and it's amazing how much brain power I've got to spare now I'm not constantly thinking about food. I don't stuff myself and I eat healthily, but I allow myself to eat enough and enjoy it. My boyfriend hasn't said a word about me getting fatter, but he has noticed that our sex life has approximately quadrupled."

Peter, 32, said: "There's nothing nicer than rolling away from dinner all full up with lots of delicious food, it makes you feel all's right with the world."

Is all this munching a sin? Of course it's possible to go too far, and as a nation we are gradually swelling - planes and trains were discreetly adapted a few years ago to cope with a larger clientele. But we maintain a modest position half-way up European overweight leagues - and compared to the Americans we are positively sylph-like.

Anyway, food is not just something to fill a physical gap. Eating is a social activity. The latest edition of the BBC Good Food magazine features generous portions of pasta for family suppers, and pork fillet stuffed with herbs and apricots for entertaining friends. Mitzie Wilson, editor- in-chief, says: "The trend is towards more casual, relaxed eating rather than fiddly food in tiny portions. With 'little food' you feel you have to be on your best behaviour - 'big food' is much more sensual. And when you're cooking at home it is so gratifying when people come back for seconds - there's nothing as good as people coming back for more. Entertaining shouldn't be like a business lunch - you shouldn't feel you have to impress your friends, you should be kicking off your shoes, having a few glasses of wine and a laugh."

Human beings are programmed to like food, explains David Booth, nutritionist and professor of psychology at Birmingham University. "We are born with a very basic liking for sweetness - you even see a little sprog lick his lips and smile. As our palates become more educated and refined, tastes, textures, smells, colours and sights all add to the thrill. And there is also a social element - context, ambience, emotion all add to the pleasure. Chocolate, for example, is associated with rewards, treats, romance."

So clearing your plate will make you happy, which is as good an excuse as any. And we are not the only nation with a healthy appetite. A friend recently accompanied some Belgian business contacts to Belgo. He was impressed by their superior capacity. "They said 'Only one kilo! Hah! At home we always eat two'."


John, 26, is a solicitor

Actually, this isn't an entirely typical day for me, because I had a misunderstanding about the fact that we were going out for dinner at a Brazilian restaurant, so when I got home, I went for the fridge. But I didn't feel too bad, actually, not too stuffed at all. Now I'm in my mid- twenties, I find I don't eat so much. When I was younger, I'd have three doughnuts and a pint of milk for breakfast every day. The sandwich lunch is typical for me - I always have three sandwiches at lunchtime, at my desk. I don't think I eat too much, and I'm perfectly healthy and not overweight.

9am Apple juice.

10am Smoked salmon and cream cheese bagel, orange juice.

12 noon Two shortbread biscuits.

Lunch Ham and Emmental croissant with mayonnaise, Mexican tuna ciabatta, turkey and salad baguette with cranberry mayo. Orange juice.

When I got home Chicken liver pate on brown bread, with tomato chutney, a Red Leicester and mango chutney sandwich, and some hummus and bread.

Dinner Fishcake starter, plus half a portion of garlic prawns. Honey marinated pork, with rice and vegetables. I couldn't manage a dessert.


Karen, 35, is a nurse

This is a typical day for me: I might change round the chocolate, say have a Flake instead of Maltesers. I'm definitely a chocolate addict, but I always have some fresh vegetables and fruit to make up for it - I feel very healthy. I love food, and I love cooking too. I'm the kind of person who will go to a dinner party and stop off on the way home for a McDonalds, I've always been like that. I remember when I was at home I'd have a Sunday roast dinner and follow it up with egg and chips. My colleagues here agree that my intake is enormous, but we're on the go all day and I suppose that helps burn it off. I'm a size eight and I weigh about eight stone six. I agree it doesn't seem fair, when some people have to really watch everything they eat.

6.30am Yoghurt, cinnamon and raisin bagel, orange juice, coffee.

8am Topic bar and coffee.

9.30am Bacon sandwich and coffee.

11am Bag of Maltesers and coffee.

12.30pm McChicken sandwich, large fries, diet coke, apple pie. I have to say the diet coke seems a bit pointless.

2.30pm Three chocolate biscuits and tea.

4pm Cheese and pickle sandwich and tea.

6pm Gin and tonic and small bag of peanuts, then gin and tonic and bag of Mini Cheddars.

Dinner Two lamb chops, saute potatoes, peas, gravy, one of those small Tesco dessert things, and a piece of chocolate cake.