Insidious ploys that mean you can never stop at just one crisp

From the shape that perfectly fits the roof of your mouth to that oh-so-satisfying crunch ...

THE family- sized bag of crisps was for my lunch guests to share, but it barely made it back from the supermarket before I gave in to the urge to tuck in. After grabbing a handful, I closed the packet, telling myself that would be it. Yet half an hour later I’d scoffed the lot.

I’d like to say this was a one-off, but my crisp habit frequently careers out of control. I could happily eat nothing but crisps for dinner, and at any other time.

I’m not alone. We are a nation of crisp fanatics, consuming about six billion packets a year. That’s one ton of crisps every three minutes, or nearly 100 packets per person — more, it is thought, than anywhere else in Europe.

I decided to take a look at what makes crisps so moreish — and the toll our habit is taking on the nation’s health.

TERRIBLE TRIO

IN SALT, Sugar, Fat: How The Food Giants Hooked Us, author Michael Moss reveals how crisps are made irresistible.

Salt provides an arresting sensation on first contact with the tongue, called ‘the flavour burst’ by the food industry.

Fat from the oil in which crisps are fried gives ‘mouthfeel’ — experienced through the trigeminal nerve, which sends pleasure sensations to the brain.

Sugar, meanwhile, isn’t only present in the potato starch but is often added by manufacturers to make crisps all the more enticing.

Our desire for foods containing fat, salt and sugar is thought to have come from our hunter-gatherer ancestors, who craved high-energy foods. Sensible then, perhaps, but a source of problems now cheap junk food is readily available.

THE PLEASURE PRINCIPLE

WORRYINGLY experts have found similarities in the brains of crisp-lovers and drug addicts.

Dr Tony Goldstone, a neuroscientist at Imperial College London, found that when overweight people saw photos of junk food their brains responded like those of alcoholics and drug-addicts did when shown wine or cocaine.

A German study discovered the reward and addiction centres of rats’ brains were more active when fed crisps than a powdery mixture of fat and carbohydrates of the same calorific value.

Dr Tobias Hoch, of Friedrich Alexander Erlangen-Nuremberg University, believes molecular triggers in crisps stimulate these reward centres.

So why is my husband content with a few crisps, whereas I have to scoff a packet (or two)?

Dr Hoch explains: ‘Possibly, the extent to which the brain’s reward system is activated in different individuals can vary depending on individual taste preferences.’

CRUNCH TIME

IT IS a crisp’s texture, as much as its taste, that keeps us reaching for more. ‘Research has found that the more noise a crisp makes when you bite into it, the more you will like it,’ says Moss.

Makers have spent a small fortune to discover that ‘the perfect break point’ occurs when crisps are put under four pounds of pressure per square inch.

Ever eaten three packets of Wotsits in a row without feeling full? That’s no accident either. Corn snacks that dissolve on the tongue, such as Wotsits, Monster Munch and Cheetos, are so easy to eat that our stomachs have no time to tell our brains they’re full before we’ve overindulged.

Food scientist Steven Witherly says this melt-in-the-mouth sensation is called ‘vanishing caloric density’. He explains: ‘If something melts quickly, your brain thinks there’s no calories in it… so you can keep on eating it.’

PACKETS OF HISTORY

THE FIRST recipe for crisps was printed in British chef William Kitchiner’s cookbook, The Cook’s Oracle, in 1822.

Since then they have become a national institution.

The Walkers crisp factory in Leicester — the largest in Britain — has machines that get through 2,000 razor blades a day cutting each potato into 45 wafer-thin slices, before frying them in rapeseed or sunflower oil.

SAVOUR THE FLAVOUR

UNTIL the mid 20th century crisps came only with salt, but as cellophane packaging replaced greased paper bags to extend shelf life, more flavours came in.

These have become wackier, from langoustine and lemon to chocolate and gin and tonic.

Because our taste buds can detect five tastes — bitter, sour, sweet, salt and meatiness — manufacturers often use flavours that use as many of these as possible.

Pringles Texas Barbecue flavour contains citric and malic acid and monosodium glutamate (MSG) as well as salt and sugar, stimulating four out of five of the tastes for maximum impact.

Reassuringly, good old-fashioned Cheese and Onion remains Brits’ favourite flavour. IN A competitive market nothing is left to chance, not even the shape of the crisp — Pringles, a blend of potato and wheat, are curved so they reach as many

CLEVER MARKETING

taste buds as possible. Gourmet crisps have been developed to convince health-conscious adults that some fried potatoes are less bad for us.

And celebrity endorsements prove persuasive among children. A Liverpool University study found that those aged between eight and 11 were much more likely to choose Walkers crisps over unbranded snacks, after watching Gary Lineker advertising them on TV.

WHAT’S THE DAMAGE?

CRISPS are the largest single contributor to the U.S. obesity epidemic, a New England Journal of Medicine study of 120,877 women and men found.

Dr Dariush Mozaffarian, an assistant professor of medicine and epidemiology at Harvard Medical School, who did the research, said the refined carbohydrates in a packet of crisps (typically more than 50 per cent) disturbs blood glucose and insulin levels, causing an imbalance which ‘leads to less feeling of fullness, increasing hunger and larger amounts of food consumed over the course of the day’.

Nutritionist Dr Zoe Harcombe, author of Why Do You Overeat? adds: ‘The body converts this excess glucose into glycogen by releasing insulin to the blood stream, which can cause a subsequent slump in energy levels and symptoms including headaches, irritability — and a craving for more crisps.’

FAT LOT OF GOOD

IN 2006 the British Heart foundation warned that eating a packet of crisps a day was the equivalent of drinking five litres of cooking oil a year. Manufacturers cut saturated fat levels in response, but the frying process still gives cause for concern. Tests have shown that when starchy foods, like crisps, are fried at a high temperature toxic chemical acrylamide is produced. A Bradford Institute for Health Research study linked acrylamide intake in crisp- eating pregnant women to lower birth weight and head circumference in newborns. Both factors can lead to delayed development of the brain and nervous system, type 2 diabetes and heart disease.

THIRSTY WORK

THE average packet of crisps contains about 0.5g salt — nearly 10 per cent of the recommended daily intake. Although the link between too much salt and high blood pressure and heart disease is well known, the knockon effect of salt in crisps arguably makes it more damaging. ‘The salt makes us thirsty as it knocks our sodium and potassium levels off balance,’ says Dr Harcombe. ‘ What we should do is drink water, which contains potassium, to restore the balance, but what we’re more likely to do, in a social setting, is turn to alcohol.’

TASTE TRICKERY

ONE OF the most controversial additives in some crisps is MSG.

Clinical trials are inconclusive but research has suggested MSG — which Walkers don’t use but is present in some Pringles and Monster Munch — can cause kidney damage in animals and lead to depressive behaviour in rats.

It also seems to make crisps even more enticing by tricking the brain into thinking the meaty flavour denotes protein.

Dr Harcombe says: ‘The processed food industry is so cynical and ruthless it will stop at nothing to make sure as many people as possible are addicted.’