Honey, have you packed the Holiday Fat Map?

I remember the moment my food fatigue set in. I was at a business lunch in New York a fortnight after moving to the US and a third of the way through my ranch dressing-soaked excuse for a salad when the scene took on the quality of a nightmare. The snuffling noises emanating from a nearby table – where a man was inhaling heaped forkfuls of spaghetti carbonara – seemed to be growing grotesquely loud; the woman reaching for a spoonful of her son’s chocolate sundae predatory in her gluttony. All around, diners were engaged in the same robotic hand-to-mouth gesture, like drones with a grim job to do.

“Shall I wrap the rest of that up for you?” said the waiter after the meal. Alarmed by the prospect of this endless dish – every mouthful the same bland, slightly synthetic fusion of flavours – following me back to the hotel, through the lobby with its vats of preposterously large apples, past the gym with its trays of blueberry muffins, and into a room stuffed with minibar chocolates and crisps, I shouted “No!”

It was a cri de coeur : no to servings the size of Texas, no to bread that tastes like cake and dressing like cream custard; no to the 8lbs all tourists pile on when they take a fortnight’s break in America.

Because, according to new research, a two-week holiday in the US will leave you fatter than if you chose any other destination. With the Caribbean in second place on the “fat-map”, France third, Italy fourth and Greece fifth, half of those polled for the Obesimed weight-loss company blamed larger portions for the weight gain, while the same number cited “lounging around”. Four in 10 blamed alcohol, one in six admitted “finding it hard saying no to seconds”, and one in five were adamant that “free refills” were the culprits.

The real reasons for us turning into butterballs, hambeasts, chub-scouts and tuba-lubas the second we get a new stamp on our passports are, I suspect, more insidious. “Our holiday psychology is very particular,” says nutrition consultant Ian Marber, aka the Food Doctor. “Reality is suspended. 'Go on, you’re on holiday’ becomes our mantra. American portions are huge – how else did everyone there get so fat? – and even if we don’t eat as much as the locals, the average Brit will be eating more than usual.”

The problem is that when in the US, we do eat much as the locals do – and that’s too much. I’ve watched conscientious British friends enter into morbid food trances as they take in the “Buttermilk Pancakes with maple syrup” (780 calories) and “Country Breakfast Burrito” (920 calories) on their room service menus. I’ve seen their salivary glands working overtime as they order Papa John’s extra-large Hawaiian BBQ chicken pizza (3,000 calories), stopping off for a Sprinkles’ Red Velvet cupcake and full-fat latte (580 calories).

It’s partly a linguistic thing, a desire to gorge on the cartoonish grossness of American culture. And so you order a “Blimpie’s meat sub supreme” because it’s an absurd thing to hear yourself say out loud, and “a stack of French toast” because it’s amusing – and obscene – for anything non-industrial to be served by the stack. Like wearing a beret in France, or buying a fake Gucci handbag in Italy, overeating is something you do in America.

To an extent, the same can be said of the Caribbean. “With all-inclusive holidays,” says Marber, “the clue is in the title. And because the food isn’t 'local’, it’s bound to be Americanised, with high fat and simple carbohydrates disguised as a main course.” So those all-you-can-eat buffet breakfasts (where the real challenge is to see how much you can eat before you’re asked to leave), beach snacks – beef patties (380 calories), fried dumplings (338 per dumpling) – and Pina Coladas (more fattening than a Big Mac at 644 calories), will help you pile on a prodigious 7.4lb.

It’s in Europe that holiday gluttony becomes less easy to explain. Neither France nor Italy are nations of blubbernaughts. The locals may not overeat, but we certainly do when we go there, gaining an estimated 7.3lb in France and 7lb in Italy.

“With those countries, it has to be the Continental breakfast,” insists Marber, “basically no more than a basket of sugar, and which leads to an insulin spike and lethargy. Alcohol also plays a huge role, as do the cocktails with nibbles before dinner, which ruin one’s resolve.”

Journey to Greece (6.9lb), Portugal (6.7lb), Spain (6.6lb) or Turkey (6.3lb), and you’re still likely to fly back with jeans tight enough to cause DVT, and a memorable selection of fat-snaps (“there we are with our bingo wings outside the Sagrada Familia”).

“What amazes me is the pre-holiday fervour around losing weight, the importance of looking good in that new bikini or those shorts, and then how quickly control is lost once people leave British soil,” says clinical nutritionist Carole Symons from The Third Space Medicine, London. “There are many concerns associated with rapid weight gain. It can initiate yo-yo dieting, which can in turn predispose one to eating disorders.

“Rapid weight gain and weight loss can also lower the body’s natural 'killer cells’, which protect your body from diseases such as cancer, flu and the common cold. And it can lead to blood sugar problems predisposing one to diabetes, high cholesterol, gall bladder problems and high blood pressure. What’s more, if all the holiday weight isn’t lost and the pattern repeats itself year by year, something as small as a 1lb net gain per summer holiday can result in an extra stone over 16 years.”

The answer? Abstain for the two weeks you’ve been looking forward to all year? Never going to happen. Adopting the “punish and reward” ideology of Americans, who offset the excesses of their holidays with a gruelling workout every morning? Can’t see us taking that up, either.

No, aside from drawing up your own “thin-map” and travelling the developing world in search of a particularly vicious case of amoebic dysentery, self-control – that insufferably tedious term – would appear to be the only option. As some wise old thin bloke once said: “Discipline weighs ounces, regret weighs tons.” Happy holidays!