Dr O'Connell, whose book also discusses melatonin, light visors and circadian cycle, is much more fun. "Alcohol is an important sedative," he says, "which can be usefully employed as a sleeping pill." And because alcohol, unlike the sleeping pill, has been around for thousands of years, we know exactly what it's going to do to us. As it's a diuretic (it makes you want to pee more), he advises against "large volume" drinks like pints of lager or daiquiris, gin and tonics and screwdrivers; instead stick to "higher-proof strengths" like whisky, brandy, cognac, or "soporific clarets and red riojas" (yes!). Champagne and white wine are likely, unfortunately, to wake you up with heartburn or indigestion. He keeps a few cans of Diet Coke in the seat pocket in case he wakes up thirsty. Leslie would not approve.
When I challenged Dr O'Connell about the raw carrot semi-fasting method, he was dismissive. "If you don't eat or drink then your body will think it's night time and that would be a disaster if it's light outside. The important thing is to set it to the body clock of destination - do this 24 hours before you leave, if possible, and set your watch to your destination time as soon as you get on the plane." His book is full of complex strategies: London to Singapore, a 13-hour flight departing at 11am, means boarding the plane at what is 7pm in Singapore. So cheers - have a pre-dinner drink and wine with the meal, go to sleep five or so hours into the flight and don't wake up for breakfast. When you're flying New York to London on an evening flight, have an early dinner first, in the airport or at a restaurant in town, drink plenty of wine with it and then crash out for the whole flight. Still, he admits you can go too far with the booze. Yeltsin can handle his drink well enough at home, says O'Connell - but look what happened when he'd overdone it on arrival in Ireland. The combination of jetlag and alcohol rendered him incapable of getting off the plane. Bush, on the other hand, found sleeping pills and jetlag incompatible - they affected his speech (and, perhaps, resulted in that dinner-table vomit in Japan in the early Nineties).
Sarah Mower, former fashion features director at Harper's Bazaar, used to commute between London and New York. She agrees with O'Connell about sleeping pills. "Americans are always moaning about jet lag and seem to get sleeping pills prescribed very easily. But they're in a worse state on arrival than anyone who's had something to drink. They're slurring their speech for two days afterwards." Mower, who has three small children, feels "in a permanent state of jetlag in everyday life" and hardly ever sleeps more than four hours at a time. This helped her cope with the constant flying, as did sharing a bottle of champagne on board with Harper's Bazaar editor Liz Tilberis. Kathy Lette, who does the London-Sydney long haul with her "two rug rats" says booze is only way to cushion the awfulness. "Otherwise I'd jump out. The stewards fix me up with an intravenous drip of champagne from first class as long as I tell them jokes in return. When I get there I dive into the beach at Bondi and everything's cured."
Professor Simon Folkard of the Medical Research Council is unimpressed. "Alcohol helps you to fall asleep but the quality of sleep is appalling. The main reason for jetlag is dehydration and alcohol will exacerbate this." Perhaps the trick is not to take it all too seriously. Although Dr Jim Waterhouse at John Moore's University in Liverpool is convinced, taking all the evidence into account, that alcohol will worsen jetlag, he agrees that adjusting to your new local time as soon as possible is important and that "people don't die of jetlag, so OK, why not enjoy yourself and have a drink. You won't be that debilitated."
For more information, see 'Jetlag: How To Beat It' by Dr David O'Connell, Ascendant Publishing, 11.99; The Jetlag Clinic, 41 Elystan Place, Chelsea Green, London SW3, 0171 584 3779; 'Jet Smart: Over 200 Tips for Beating Jetlag' by Diana Fairechild at http://www.flyana.com