15/07/2014 08:00 BST | Updated 13/09/2014 06:59 BST

Fruit Juice - Healthy or Unhealthy?

Consultant weight-loss expert, and founder of, Dr. Sally Norton reviews the science behind the latest headlines demonizing fruit juice as the latest sugar-laden contributor to the UK's rising obesity

We have all been shocked (and chastened!) by the news that a can of coke contains around 9 teaspoons of sugar - which is over the daily recommended total in a single can! Rather than the 'healthy' alternative, it seems the diet versions may not be much better for us, with some studies showing that they can even lead to more weight gain than the full-sugar versions. Not to mention the sweeteners, which replace the sugar in these low-cal options. Though there is no definite evidence that they are harmful to our health, we are consuming them in greater and greater quantities, sometimes above the recommended 'safe' levels. Plus they do nothing to help reduce our sweet tooth and thus, our sugar cravings.

So, on the face of it, up against a can of coke, fruit juice seems a great 'natural' alternative - and the image of breakfasting on a bowl of cereal with a glass of orange juice is ingrained in our nutritional psyche as a 'healthy start' to the day. Yet even this seemingly virtuous beverage is under attack from the 'Sugar Police' in the latest headlines - but why?

Well, sad to say, but fruit juice and smoothies can contain even more sugar than coke - up to 12 teaspoons in a glass! Some juices not only have fruit sugars, but may have added sugar, too - why on earth do some manufacturers do that?! These 'added sugars' only fuel our palate into craving sweeter and sweeter foods - increasing our consumption and our weight.

The sugar from fruit is 'natural', for sure, but that doesn't mean it is good for you - deadly nightshade is natural too! Don't be lulled into the marketing ploy of an 'all-natural' juice - sugar is sugar, and we need to keep on top of our consumption.

The type of sugar in fruit is called fructose - a sugar that doesn't cause so many blood sugar spikes (the long-term effects of which can lead to type-2 diabetes) but one that may increase the amount of fat stored in the liver - which in turn can cause disease. A small amount of fructose in an apple is unlikely to cause problems as it is mixed in with fibre anyway, which helps protect us from the sugar's effects and slows its absorption. However, strip the fibre away to leave just the juice and it is absorbed more quickly. Not to mention the fact that you are unlikely to be satisfied with the juice of just one piece of fruit. In fact, manufacturers proudly shout about the amount of fruit that they have crammed into one bottle of juice. OK, perhaps that provides a few more vitamins (though sitting on a supermarket shelf is likely to degrade them) - but squeezing half a fruit bowl's worth into one serving delivers a shedload more sugar, too.

So, you will be more full, and take in less sugar if you have an apple and a glass of water than straight apple juice.

Does that mean a total no to fruit juice? Of course not. Anything in moderation is good. Try blitzing your own juice using a lot of veg and a hint of fruit....... Or flavor some water with ginger, lemon or mint.