Half way through this entertaining slice of culinary nostalgia, Sue Perkins describes her week-long stint as a 1970s woman like this: "Non-stop Black Forest Gateaux and indiscriminate sex". She could well have been right, although I have no idea - I was born in the early 1970s and sort of can't remember much about what I ate except for the odd Findus Crispy Pancake. It turns out that 1970s food was stuffed full of additives and preservatives and colours and sugar. Basically, the 1970s was where it all started to go wrong.

In previous episodes we saw Giles and Sue eat nothing but Victorian food, Restoration food and food from Wartime era. Those episodes were all marvellous entertainment, providing as they did plenty of titbits about how we used to live in those days and wince at the kinds of foods they ate.

The Seventies, on the other hand, was relatively recent (heck, I was alive during them) and I wondered I would learn as much as had in previous episodes.

Still, it was on with it. Giles went to the hospital to take gut readings, and it was revealed Seventies humans ate more 750 calories per day than we did... yet they were much slimmer than us. More exercise, apparently.

Anyway, Giles assumed the guise of a Seventies advertising executive, while Sue became a housewife with a part time job. They had award-winning chef Mark Hix to help them out with all their Fanny Craddock recipes and general Seventies food.

Their first meal of the week was bacon and mushroom stuffed (some weird Craddock concoction), grilled grapefruit and eggs and soldiers. They loved the eggs.

Giles then went to one of those wine bars that became popular in the Seventies and mainly drank booze. Tequila Sunrise and Harvey Wallbanger for starters, grilled red mullet, some Chardonnay, Duck a L'Orange and créme brulee was the meal and Giles, with big collars and waistcoat slowly got drunk.

When he got back he snuggled up on the sofa, turned on the TV and ate his dinner on a tray. Yes, it was the age of the TV dinner... and also the age of food that came out of packets. All Sue needed to do to cook tea was add water to the Smash, bung in some faggots into the oven, boil some cod in a bag and open a tin of vegetables. It was that simple and heralded the invasion of convenience.

In a bid to relive their childhood days, the pair went back to Sue's school in Croydon on day two. There they sampled school dinners, which meant liver and bacon cabbage, and chocolate sponge and chocolate custard. Sue was back in heaven with the chocolate sponge - she maintained that she had tasted nothing better since her school days.

Day three saw the pair explore Sue's job as a part time travel agent. Travelling abroad and package holidays were suddenly very popular and Sue and Giles sat in something that looked like an aeroplane and ate a meal - salmon and caviar on biscuits; Don Perignon; chicken, asparagus, foie gras; poached oranges in Grand Marnier; lots of cheese.

Speaking of cheese, Sue and Giles then went to a dry ski slope to demonstrate the popularity of ski holidays. They had a fondue. Then they had a sweet fondue. Sue looked as though she was going to throw up by the end of the 'meal'.

Day four and it was time for some diet food for Sue. Ryvita, cottage cheese and strawberry Slimfast. Giles, meanwhile, demonstrated how much more exercise the average Seventies person did compared to us fat layabouts who sit at the computer too much. By walking to work, playing a spot of tennis, riding bikes, skateboarding and climbing up and down stairs at liftless offices Giles burned four million calories.

Back at the ranch, Giles got to grips with his indoor bar (which were becoming popular in the Seventies) and rustled up some disgusting cocktails. Then it was on to tea. Not any old tea... a tea that had been voted for by random people from 1973, who answered a questionnaire about what their perfect, dream meal would be. Tomato soup (dream-like indeed), prawn cocktail, Steak Diane with chips and sherry trifle.

Day five saw the pair indulge in another the Seventies great pastimes, swinging. They met a sex writer and a bloke who was an original swinger from back in the day. During their lunch they discussed what happened when the car keys were swapped. They also ate things called French Kiss, Potato Masoch and Nymphomaniac Surprise. Giles tried to get off with the sex writer.

Fast forward to day seven and it was time, after a cooked breakfast in bed, their big, final meal of the show. It was to be a great big cocktail party and Mark pulled out all the stops in the canape department - cheese and pineapple; coronation chicken col au vants; steak tartare; roast chicken and green mashed potato; Swedish bird's nest; haddock mousse; and salmon and cucumber in Liebraumilch jelly. Then there were the gateauxs. Lots of them.

Giles also made some blue cocktails, where everyone got fairly smashed to. In fact, judging by a cocktail recipe book of the time, people in the Seventies drank an extraordinary amount. The book recommended that a guest should have half a bottle of spirits every two hours.

Despite all he crap they had eaten during the week, Giles and Sue really rather liked the Seventies. For Sue it was chance to really live out the decade, as opposed to viewing it through the slats on a bannister from the top of the stairs as her parents hosted dinner parties (as she did in real life), but for Giles it was seemed like great fun in comparison to today's do-gooding poe facery.