When you've got the munchies nothing but immediate gratification will do. So many of us suffer a dieting downfall and end up snacking on unhealthy options like crisps and chocolate. Yet by choosing wisely, snacking can be a positive and healthy contribution to your diet

Why we snack
There are many reasons why we snack: comfort eating, boredom, a quick energy fix, or just because of a desperate 'I want it now!' feeling. Snacking is linked to the fact that we're designed to graze. Our Neolithic hunter-gatherer ancestors ate what was available when they could get it and didn't necessarily sit down to square meals. They also didn't have a fridge full of temptation and food adverts constantly screaming at them.

It's not me, it's my brain
There's no doubt that sugary, fatty and salty snacks are attractive and addictive. Attractive: we're designed to enjoy fat, sugar and salt because during evolution these were scarce commodities. Addictive: any food that we find pleasurable triggers the same brain chemical pathways that satisfy our pleasure centres in the brain and reinforce addictive behaviour. Add the fact that sugars and refined carbohydrates (white bread and white flour products) significantly contribute to blood sugar swings and it's easy to see why snacks such as biscuits and sweets are so tempting. When we're feeling low and lethargic, they quickly lift us out of a blood sugar rut, but in the long run contribute to the problem.

Change your view of snacks
Think about snacks as mini-meals and not as treats. By ditching the 'I deserve a little reward' thought pattern and thinking of snacks as ways of feeding, nurturing and supporting your body, you can change the choices you make. Instead of eating three large meals a day, eat five or six small, healthy meals. This helps to boost blood sugar levels in a positive way. Additionally, by eating foods that provide vitamins, minerals, antioxidants, fibre, proteins and healthy unsaturated fats, your body is nourished and excess weight is lost.

Worst snacks
As a rule of thumb, anything over the following amounts is a bad snack (these are considered absolute upper limits anyway and lower amounts than these are recommended):

• 10g of sugar per 100g of product
• 0.5g sodium per 100g of product
• 20g of total fat per 100g of product

You're probably already familiar with this list:

• Colas
• Sugary coffees or teas
• Crisps
• Sugary breakfast bars
• Biscuits
• Pies (sweet or savoury), as they're nearly always high in fat
• Fruit juice based winding snacks (which are mainly sugar and not fruit with fibre)
• Sugary breakfast cereals
• Confectionery

Four snacks for those with a sweet tooth
The idea is to break the need for intense sweetness. Do this by eating lots of fresh fruit, which is naturally sweet, and by including protein with each snack to help stabilise blood sugar levels. Try:

• An oatcake on its own or with nut butter
• A yoghurt, topped with flaked coconut and chopped dried apricots
• Cheese cubes with grapes
• Strips of ham wrapped around pitted prunes

Four snacks if savoury is your thing
Aim to satisfy it with lean protein sources and eat snacks full of flavour from herbs and spices instead of from salt. Try:

• Half an avocado with a few prawns
• Vegetable sticks or breadsticks with dips such as hummus, guacamole, mushroom pate, tzatziki, or mackerel pate
• A cup of warming soup (fresh soups are available in cartons)
• Bruschetta - toasted bread (ciabatta is best) brushed with olive oil and garlic and topped with chopped fresh tomato and shredded basil leaf or spread with tapenada (olive or sun-dried tomato paste available from supermarkets)

Four snacks to take to work
Have something easily to hand in your desk drawer or in the glove compartment of your car, it helps to reduce the urge to buy something unhealthy on the run. Try:

• Dried apple rings or raisins with a few unsalted nuts
• A small packet of low-salt corn chips with salsa dip
• Mini rice cakes and a cheese stick
• Good quality high-cocoa content dark chocolate is much lower in sugar and ideal when nothing but chocolate will do

Four ideas for mid-morning snacks
Keeping energy levels up during the morning means we often dip into the biscuit tin. Start with a blood-sugar stabilising breakfast with protein - such as an egg, or wholemeal toast, porridge or low-sugar muesli. Always add fruit. It is well established that sugary cereals and white bread lead to reduced concentration and energy mid-morning. Try:

• Rye cracker with cottage cheese or hummus
• A fruit scone or banana muffin
• A mashed banana piled on some rye toast and sprinkled with cinnamon
• Biscuits with high fruit content such as fig rolls and Garibaldi

Four ideas for mid-afternoon snacks
It's probable that we're designed to snooze mid-afternoon (returning to our Palaeolithic ancestors), hence the effectiveness of siestas or power-naps. But if you can't do this, the worst thing is to keep going on 'empty' by propping yourself up with sugary snacks. Try:

• Oat and raisin flapjacks (choose a good quality brand which is not too fatty, or even better, make your own)
• Wholemeal breadsticks with low-fat cream cheese and pineapple
• A slice of fruit loaf and an apple
• If you're desperate for sugar, make it a healthy fix. Drink a fresh smoothie, free of added sugar, with loads of delicious fruit in it for fibre (this is not the same as fruit juice, which does not have the fibre in it and provides too strong a blood sugar hit). These are available from shops or you can make your own

Four sleepy snacks
The worst thing for achieving deep sleep is too much alcohol - you might pass out but stay at an unrestful level of sleep. On the other hand, calcium and oats are well-known for their soporific qualities, hence the popularity of oat-based milky drinks. But commercial brands are often too sugary. Try the following:

• Blend finely milled oats with a cupful of milk or calcium-enriched soya, and add a teaspoon of honey for (controlled) sweetness
• If you wake in the night this may be due to blood sugar dips, so keep half a banana or an oatcake by the bed to snack on and lull you back to sleep
• Lettuce is rich in a compound that helps to induce sleep, so enjoy a salad in the evening
• Herbal teas that aid sleep are vervaine and camomile. They're much better choices than caffeine-laden coffee or tea, or alcohol, which interferes with deep sleep