Snack attack: 'Grazing' used to be king, but now experts say it slows metabolism, and can cause tooth decay and diabetes

For years, nutritionists have been telling us to graze - eat little and often - to keep up our energy levels and as a tactic to avoid overeating unhealthy food.

The problem with grazing is that many people ignore the bit about eating only a little, hearing only the message to 'eat often' - the result is we've become a nation of snackers.



Furthermore, we're snacking not on healthy foods, but on chocolate, crisps and other calorie-laden products.

Between meals: Experts now believe that we should go back to three meals a day, and cut out the snacks in between. (Posed by model)

Clearly, eating lots of junk food is not good for the waistline. But now, some experts believe that the very principle of eating between meals - whether it's healthy or junk food - is the real problem.

They say snacking makes us even more hungry; it also interferes with the body's ability to burn fat, leads to obesity and type 2 diabetes, as well as tooth decay.

What we should really be doing, it seems, is going back to three proper meals a day, with no snacks in between.

'For many, snacking is a major cause of weight gain,' says Professor Stephen Atkin, head of diabetes and metabolism at Hull York Medical School.

Adds Naveed Sattar, professor of metabolic medicine at Glasgow University: 'Snacking gives us extra calories and the fact is, extra calories make us fat.'

But not only are snacks often highly calorific; eating all day also undermines our body's ability to burn off fat.

If you must... Too many people are eating chocolate and crisps, where the perfect snack remains fruit and nuts

When we eat, our body releases insulin - a hormone that helps carry sugar into the cells to burn as energy. This sugar energy will keep us going for around three hours, after which our bodies will start using energy from our fat stores.

If we can hold out for four to five hours between meals, we burn more fat. 'Fat is burned as soon as your carbohydrate stores fall and you start the mobilisation of fat for energy,' explains Professor Atkin.

Snacking also means that organs such as the liver and pancreas are under greater stress, as blood sugar and fat levels stay higher throughout the day, says professor Sattar. This also increases stress on blood vessels and, perhaps, the heart.

'In my view, the ideal would be not to snack at all,' adds Professor Atkin. 'It's normal to feel hungry before a meal.'

Many people believe that if they don't eat little and often they run the risk of becoming hypoglycaemic - when blood sugar levels become low, causing mood swings, lightheadedness and feeling shaky.

The theory is that eating six small meals a day keeps blood sugar levels stable. However, while cases of genuine hypoglycaemia exist, they are rare and should be carefully checked by laboratory tests.

In fact, unless you are diabetic, your body is very good at regulating blood sugar itself and there's no need to eat constantly, explains dietician Lyndel Costain.



'We can actually go a long time without eating,' she says. 'Assuming you've had a reasonable meal, you can go four or five hours without eating.



'And if you start to feel hungry, it will be because most of your food has been digested and your internal appetite regulators are sending messages for more food.

'But your blood sugar won't go down so low that you have a hypo, unless you have a genuine problem with your blood sugar.'

Indeed, rather than stabilising blood sugar levels, snacking on sugary, high-carbohydrate foods is more likely to make them fluctuate wildly - which can make you feel more, rather than less hungry.

As nutritionist Zoe Harcombe explains: 'If you eat cake or biscuits, the high sugar content causes you to release too much insulin and your blood sugar ends up lower than it was before you ate, as your body tries to compensate for the sudden sugar intake.

'So, although you might feel great 15 minutes after eating, 40 minutes later you will start to feel tired and hungry again. And after 90 minutes you'll feel ravenous, so you'll eat another high-sugar snack.'

Snacking is also bad for our teeth. When we eat sugary foods or fruit, the pH in our mouths becomes more acidic and this is when tooth erosion and decay begin. our mouths remain in an acidic state for about 20 minutes before returning to a neutral pH, says Janet Clarke, from the British Dental Association.

'The more often we eat, the more frequently our teeth are attacked and are likely to decay.

'For this reason, I have an apple and an orange on my desk which I shall eat as part of my lunch, rather than a mid-afternoon snack.

'But I would hate to put people off eating fruit as a snack, as it gives you fibre and vitamins and is healthier than biscuits or cake,' she says.



Of course, the problem is that the urge to snack is hard to resist, says Professor Sattar. 'There are so many snacks and temptations around these days. You go into a garage to buy petrol and you're faced with aisles of sweets.

'You miss breakfast and you can buy a bacon sandwich on your way into the office - the availability of calorie-laden snacks is a far cry from 25 years ago. But it's essential to change our way of eating.'

If you must snack, Professor Atkins says that the worst thing you can do is to eat on autopilot.

'Snacks are readily available and we are all very busy. So it's easy to eat when you're doing something else without thinking about what you're eating - then you accidentally overeat.'

Most of us are guilty of this from time to time. We might have an important work deadline, or a big family event to organise and so, feeling busy, buy snacks from vending machines, have a muffin with our coffee, or eat endless biscuits to keep ourselves going.

But we'll probably end up overeating by doing this.

A French study found that women who were distracted while eating notched up more calories.

The researchers at the Hopital Hotel-Dieu, Paris, observed a group of women whom they described as 'restrained eaters' and who watched their weight.

The scientists discovered that if there was a distraction such as television, the women ate significantly more calories. one way to help you to get through to your next meal without snacking is to eat lowglycaemic foods at mealtimes such as porridge, baked beans, lentils and yoghurt, which release energy slowly and so keep you feeling fuller for longer.



And if you get really desperate, swap to low-calorie snacks. 'If you don't have the wi l lpower, make healthy snack substitutions instead,' says Professor Atkin.

This means swapping cakes and biscuits for fruit. 'It will take about four weeks to get used to it, but after this time you'll find it easier, and snacking on fruit is an acceptable life-long eating programme.

Professor Sattar, who has a family history of type 2 diabetes, has trained himself to snack on low density calories such as fruit and have less high-density snacks such as chocolate. 'This change took several months, but I now eat a quarter of the cakes and biscuits that I used to,' he says.