Can't stop nibbling all day? Worried your penchant for between-meal bites is ruining your diet?

Logic says if you don't want to end up super-sized, cut back on snacks. But - surprise - it turns out that swearing off between-meal eats can have a negative effect on your waistline: snacking may help you eat less in the long run.

"Studies show that people who avoid eating between meals may end up consuming more kilojoules overall," says Keri Glassman, author of The Snack Factor Diet. "When you're famished, your blood sugar is low and your defences are down, so you don't necessarily make the best choices."

To snack without adding bulk to your backside, fill the pantry with foods that have built-in willpower - and which will last you beyond the silly season. When you go shopping, pick bites that fall into these three super snacking categories for a no-gorge guarantee.

Just add air

Foods that are pumped full of air make your stomach feel inflated without giving you a belly that bulges as much as St Nick's sack of toys.

In a study published last year in the journal Appetite, Dr Barbara Rolls, author of The Volumetrics Eating Plan, served visitors to her US-based lab, either some crunchy cheese snacks or more aerated puffy cheese snacks. Those munching the puffier snacks consumed nearly 75 per cent more by volume, but they took in 20 per cent fewer kilojoules.

"When something is full of air, an equal amount of it looks bigger, so people tend to take in fewer kilojoules," says Dr Rolls.

So nosh on air-puffed snacks to eat more without your gut suffering the consequences - and you might even manage to stretch your snack over the entire Spicks and Specks Christmas special instead of blowing it all in the first five minutes.

Think thick

As far as your muffin top is concerned, all kilojoules are created equal. But, like your Uncle Dave when it comes to Chrissie presents, your brain plays favourites.

"Some liquids don't seem to trigger the same response in metabolism and hunger suppression that solids do," says Dr Susan Swithers of Purdue University's Ingestive Behavior Research Center in the US.

Sharon Natoli, nutrition expert, explains: "If you down kilojoule-containing liquids, such as sweetened soft drinks, cordials, juices or milk drinks, you still eat the same amount you would've done if the beverage had been kilojoule-free (like water or herbal tea)."

The exception for liquids is soup - this tends to fill you up, so it's a smart entree choice.

The good news is that scientists speculate thicker liquids, such as smoothies, are recognised as food by your brain's appetite centre, so they can help you get to that couldn't-eat-another-bite feeling.

"The more solid the food or beverage, the greater the filling power," says Natoli. And Dutch researchers have backed up the idea with a study published this year in the International Journal of Obesity.

After offering unlimited amounts of chocolate in three forms - milk, custard and a beverage with a consistency between the two - they found (in addition to, we bet, a lot of eager volunteers) that those who had the choc milk consumed 30 per cent more kilojoules than those who ate the custard. Meanwhile the mid-consistency mixture fared in the middle.

Spice up your life

You might think your relos can't stand the heat during festive feasts, but we think you should turn it up even more. Throw some spices into the mix - they're key ingredients for weight loss.

One study showed that spiking soup with a big dose of chilli led to an intake of fewer kilojoules in subsequent meals. Chilli may cause thermogenesis (your body literally heats up, burning a few extra kilojoules in the process.) Plus, the hot sensation slows you down:

"You simply can't eat spicy cuisine quickly," says nutritionist Judy Stern.

This means you've got time to realise you're full before you've finished a whole big meal.