In the health and fitness world things are generally divided into; “Do this, it is good. Don’t do that, it is bad”. Very black and white.

It’s just easier that way when it comes to getting messages out there. But the truth is, there is a huge amount of grey in between.

In recent years carbohydrates (carbs) have been portrayed as the enemy of the people. Hollywood celebrities talked about their no carb diets while unveiling newly-honed physiques and sharing their fat loss transformations.

It doesn’t take much of that to ignite the fevered interest of tabloid papers, lifestyle and gossip magazines and before we know it, it has sunk deep into the public’s psyche.

But does it all stand up to proper, considered analysis? Well, no as it happens…

You see there are bad carbs, but there are good carbs and there are in-between carbs. So how do we sort through this carbohydrate spectrum?

There’s an interesting test devised by Dr. Sharon Moalem, a geneticist. The cracker test is something that you can do at home and it costs almost nothing.

Simply chew a cracker (as in the biscuit not the minor Christmas explosive!) until the flavour alters - it might become sweeter.

If this occurs under 30 seconds, you seem to process carbs quite well and under 15 seconds, even better. This is because of an enzyme breaking down starch into glucose sugar molecules.

But if nothing changes after 30 seconds this suggests you should be aiming for a low carb diet. It seems you are not processing well and this can result in weight gain and health problems.

Reheating can turn refined carbs - the bad ones - into something our gut bacteria loves. Pasta, potatoes and rice, revisited and reheated (piping hot, particularly in the case of rice) turns them into resistant starch foods which feed our gut bacteria and our bodies take half the calories from these than refined carbs.

Bread is not the great evil that it has been portrayed in some quarters. Not entirely anyway. It is about eating the right bread!

Mass-produced bleached stuff is bad as it dumps glucose very quickly into your bloodstream. Wholegrain rye bread is the best choice, but it’s worth checking sugar content here too as some mass-produced versions will have been pumped with additional sweeteners too.

Here’s a trick for you. How to make bad bread better.

A bit like the reheating ploy mentioned above, with bread you can freeze it. This also turns starch into resistant starch. Then toast it straight from the freezer to feed and bolster your gut health.

Carbs - the good, the bad and the ugly! Carbs are one of the key ways we get energy from food and they come from starch, fibre and sugar.

Starch and sugar end up as glucose in our bloodstream, are used as energy or stored as fat. Fibre releases energy into the body slowly, is great for the gut and doesn’t build fat.

So sugary products like fizzy drinks, sweets, refined and processed foods ramp up sugar levels and don’t do your body any favours. Fruit, vegetables and fibrous foods like pulses, nuts, seeds and oatcakes on the other hand are to be encouraged. Something to keep an eye on this Christmas!

Refined carbs - the bad ones contribute to obesity and diabetes and can even adversely affect fertility. In fact bad carbs have been shown to alter genes and can be passed on to children.

However the good resistant starch reaches further inside us and feeds good bacteria which is proven to help protect against illness and disease such as bowel cancer.

So not all the barbs thrown at carbs are valid, it’s just a case of knowing the good from the bad.