So much for Mary Poppins. All those spoonfuls of sugar are not only making us fat, they're contributing to arguably the biggest health threats facing humanity: diabetes, caused by soaring levels of obesity. Eating too much sugar can also make us tired, irritable, anxious, spotty and aggressive, and lead to insomnia.
Why do we eat so much sugar?
You shouldn't feel guilty about enjoying sugary foods. Human beings are designed to like sweet things – a clever physiological trick to save us from the poisonous plants and berries, which usually have a bitter taste.
Before the agricultural revolution, however, the only sugar we could get in our diet occurred naturally. Starchy foods such as rice, wheat, corn and potatoes – and then bread, noodles and pasta – soon became our principal source of energy. In itself, this didn't cause too many problems, until someone hit on the idea of processing raw sugar into the refined white stuff you find in most kitchen cupboards – and adding liberal helpings of it to almost every packaged and processed food on our supermarket shelves.
Most people's sugar hits start right at the beginning of the day with a bowl of breakfast cereal, laden with delicious, sweet additives. Even if you think you're being clever and eating porridge mixed with dried fruits such as raisins, you are still ingesting a fair whack of sugar. In fact, the sugar in raisins raises your blood sugar in the same way as white refined sugar. Apples and pears contain fructose, which raise your blood sugar about 50 per cent slower than grapes; berries, plums and cherries contain xylose, which releases blood sugar 50 per cent slower again.
Other culprits, aside from the obvious sugary drinks, are processed sauces and soups, which have often been sweetened.
Why is sugar so dangerous?
The UK is rushing headlong into a diabetes crisis fuelled by increasing obesity. Both conditions are linked to the intake of too much sugar and refined carbohydrates. When you pump your body full of sweet things, blood-sugar levels rocket and the body releases insulin in order to remove this excess of sugar from the bloodstream. Where does it put this extracted sugar? On your hips, tummy and bum, in the shape of fat.
Patrick Holford is the author of a new book called How to Quit without feeling S**t which treats the issue of sugar addiction as seriously as heroin, alcohol and nicotine. "The root of most of today's killer diseases is actually blood sugar problems," he says. "So the goal becomes, how do you keep your blood sugar even?"
Keeping one's blood sugar even is a bit of a vicious circle. We need to feed our bodies to stave off energy slumps, but doing that with hits of sugar will not help in the long term. Have you ever experienced that mid-afternoon slump after a carb-heavy lunch? No doubt you think it means you need more energy to get through the afternoon, and will fend off the fatigue with a biscuit or, if you're the healthy sort, apples or a banana.
The reason you slumped in the first place is because you ate too many carbohydrates for lunch, instead of a balanced meal with plenty of protein. Plugging that gap later on with yet more sugar will make you feel worse, and most likely less able to concentrate. Studies even show that plenty of non-obese people have developed insulin resistance, no doubt because their bodies have become accustomed to being fed sugar with such regularity, and have stopped bothering to break it down.
There are also strong correlations between the level of sugar in your blood and your mood. When people have low blood sugar they start feeling tired and perhaps depressed. They might become irritable, anxious, aggressive and find it difficult to concentrate. As a result, sweet foods are craved in order to bring that blood sugar back up as quickly as possible. "People who feel blue and then eat something sweet find it makes them feel better," says Holford. "They are probably low in serotonin and they've learned that sugar makes them feel better."
Regulating sugar intake
There are two main ways to balance blood sugar. The first is to avoid carbohydrates and follow a regime similar to the Atkins Diet, eating a high-protein diet. This method works for lots of people, who use Atkins as a loose blueprint for their approach to eating, rather than as a strict diet. The point is that carbohydrate, not fat, is the enemy. The demonisation of fat within the health and diet industry has led to even more sugars being added to apparently healthy, low-fat foods, in order to make them palatable.
The second way is to eat a diet that has a low "glycaemic load" (GL). The "glycaemic index" tells us how quickly the sugar from certain foods is released into the blood stream. What it doesn't tell you is how much of that food is sugar. Holford says that it is better to control the amount of sugar we eat. "Atkins limited the amount of carbs, but didn't pay so much attention to the GI," says Holford. "The GI diet limits the fast-releasing GI sugars but doesn't pay enough attention to the quantity eaten."
For example: any food with a GI food of more than 70 is considered bad. Watermelon scores 72, but in a 120g slice there are only six grams of sugar. The sugar is released very quickly into the blood stream but there is not much of it.
Oat-based cereals are better than rice- or corn-based cereals. Beans, lentils and pulses are high in carbohydrate but low-GL; brown rice and wholewheat pasta are better than white, but quinoa is much better than any of these.
The good carb/bad carb debate seems to be ongoing, and no wonder: who wants to give up that bowl of pasta? The obvious solution if you really want to pull your body back from the brink of sugar dependency would be to limit foods that are high in sugar aggressively.
How to quit
The tricky bit. The act of coming off sugar has been likened to going cold turkey on a heroin habit. This seems fairly extreme, but, as we have seen, even those of you who don't add three spoonfuls of sugar to your tea every morning are probably overloading on sugar with cereals and fruits.
"Depending on someone's sugar addiction," says Holford, "it takes between two and five days to come out of withdrawal from sugar. We've done work in schools where children are sugar-addicted. They feel flat and rough and lacking in energy for a couple of days after removing sugar. But within a week most people begin to experience more energy and more mental clarity."
Beat the sweets: Tips for quitting
1. Make a low-sugar meal plan. Swap breakfast cereal for oats and try adding low-GL cherries or berries as a sweetener.
2. Eat little and often. This means three meals and two snacks, so have something on hand mid-morning – a handful of almonds should do the trick.
3. Up your intake of Vitamin C. One study showed that a very high intake of Vitamin C reduces blood sugar levels and lowers the damaging effects of sugar.
4. Use sugar replacements. Work out the times of day you eat something sweet and replace it with something less sugary. For example: a punnet of strawberries has the same effect on your blood-sugar levels as 10 raisins, or one date. Xylose, the sugar in berries, is available in supermarkets as xylitol. You can add this to hot drinks or porridge and bake with it. Manuka honey is a great replacement for refined sugars.
5. Stay off the caffeine. Sorry: you might have decided coffee was to be your crutch while you kicked sweets, but caffeine also disrupts blood-sugar balance. Antioxidants in green tea will help repair any damage done by yo-yoing blood sugar levels.
6. Get some help. Once you've balanced your blood sugar, you need to make sure insulin is working as it should. Cinnamon supplements will help with this. Tryptophan can help reduce sugar cravings (take 200mg a day) and tyrosine will help you deal with the low moods and flatness in the initial stages (take 500mg twice a day, but none too late in the day to avoid disrupting sleep).
'How to Quit without feeling S**t', £16.99. www.how2quit.co.uk.