Sensationally Sugar Free: Delicious sugar-free recipes for healthier eating every day - Susanna Booth (2016)
The Role of Sugar in the Diet
WHAT IS SUGAR?
Table sugar, granulated sugar, demerara sugar, muscovado sugar, caster sugar… these familiar forms of sugar are all a substance known scientifically as sucrose. Sucrose is extracted from the juice of sugar cane or sugar beet and then processed and purified. The degree of refining affects the colour and size of the crystals, but they are basically all the same product. Molasses and black treacle are by-products of sugar processing that still contain a high level of sucrose. All sugars have four calories per gram.
Sugar is a naturally derived product - the problem with it is that any vitamins, minerals or fibre that were present in the original plant have been removed. This is why it is thought of as ‘empty calories’ - it offers us energy, but nothing else that the body can use. This may be useful occasionally, but most of the time it’s just not necessary, and can even be harmful.
Chemically speaking, ‘sugar’ is a word used to describe a group of related molecules. They are made up of carbon, hydrogen and oxygen atoms, which is why they are also part of a larger group called carbohydrates. Sucrose is in fact made up of two simpler sugars -
fructose and glucose - joined together, a bit like when you link two paperclips. Combinations of glucose or fructose molecules create many common carbohydrates, including fructo-oligosaccharides, maltose, maltodextrin, starch and cellulose (fibre).
Glucose (also known as dextrose)
Glucose is found in a variety of foods: as well as fruit, it also occurs in low levels in grains, beans and vegetables. It is also added to food; it’s a major component of glucose syrup.
Our cells rely on glucose to work - it’s literally the fuel we need to survive. One of the main goals of our digestive system is to ensure glucose gets into our blood in order to be carried around the body to the cells.
Ideally, our bodies would like a steady trickle of glucose rather than a massive dose all at once. The extent to which foods raise the level of glucose in our bloodstream after eating gives us the ‘Glycaemic Index’
rating, more commonly known as GI. Pure glucose is rated 100, with other foods ranked in descending order. Unless we have been exercising strenuously, it’s best to opt for foods with GI ratings of 65
and below, or combine a high-GI food (such as white bread with a GI of 70) with foods that either don’t contain sugars or very low amounts (for example, foods that aren’t carbohydrates, like eggs, meat, green vegetables, cheese or cream).
Too much glucose can cause health problems.
Fructose (also known as laevulose)
Fructose is sometimes called ‘fruit sugar’ because it is found in nearly all fruits. It tastes much sweeter than sucrose. After eating, it’s transported to the liver, where much of it is converted to glucose. This means that its GI rating is low because the process is fairly slow.
Our ancestors would probably never have consumed more fructose in a day than that which was in the fruit/honey they ate, but these days it’s possible to consume considerably more. This has been linked to a variety of health problems - see Problems caused by sugar.
Problems caused by sugar
When glucose is produced during digestion, it enters the bloodstream and a hormone called insulin is released. Insulin helps certain cells store some of the glucose in a different form, called glycogen. The result is that the blood glucose levels fall to normal. If the levels drop below normal, glycogen is turned back into glucose. When the brain detects higher glucose levels, it stops hunger signals, which is why a steady intake of glucose (such as that created when complex carbohydrates are digested) helps to keep you feeling full for longer.
On a day-to-day level, eating too much sugary food in one go will result in a sudden large increase in blood glucose levels, only for them to drop very quickly. This could contribute to mood swings and tiredness, and can also make you feel very hungry again relatively quickly, which could lead to excess calorie consumption.
Excessive glucose
As described in Problems caused by sugar, insulin is used to control the levels of glucose in the blood, with the excess being stored as glycogen. However, the body can only store a certain amount of glucose in this way, and any beyond that limit is converted to fat. A large excess can therefore lead to obesity.
Diabetes is the name given to a disease where insulin is either not produced at all, not produced in high enough concentrations or is faulty.
This means that the level of glucose in the blood stays high. Left untreated, it can cause severe health complications.
Excessive fructose
Fructose, as mentioned before, is converted into glucose in the liver.
However, the body is not able to absorb large amounts, so some of it is left over to be devoured by our gut bacteria instead. The bacteria release gas, which can lead to bloating and diarrhoea. Some people have difficulty absorbing even small amounts of fructose, a condition known as fructose malabsorption.
Processing high levels of fructose also produces uric acid, which can result in gout, and has been linked to a higher risk of obesity and high blood pressure.
Sugar and teeth
Inside our mouths lives a colony of bacteria. These bacteria like sticking themselves to our teeth using a sort of starchy glue, which is also their food - we call this plaque. The bacteria make this glue by digesting carbohydrates found in our mouths, especially sugars like glucose, fructose, sucrose and maltose. As they digest the sugar, an acid is produced. It is this acid that damages our tooth enamel and leads to decay.
These bacteria have always lived with us, but examination of the skulls of our ancestors from a thousand or so years ago often shows little tooth decay despite the lack of toothbrushes, toothpaste etc. It seems that a combination of tough, fibrous breads, vegetables and meat (lots of chewing) and limited sweet foods helped to keep the levels of plaque in check. In the UK, the widespread increase in tooth decay dates only from about 1600 onwards - the time when large amounts of refined sugar became freely available.
Modern dental advice suggests brushing before breakfast, eating sweet foods only as part of a meal, avoiding ‘grazing’ on sweet/starchy foods, drinking plenty of water (which rinses away sugars and acids) and brushing again before bed. Eating hard cheese or peanuts after a meal will help to make the mouth less acidic as well.
SUGAR ALTERNATIVES
There is no magic alternative to sugar - all have pros and cons. Some are naturally derived, such as sugar alcohols (maltitol, xylitol and others) and stevia, though humans have never before been able to eat them to excess, while others are man-made, as in the artificial sweeteners, the long-term effects of which are still not fully known.
Other options like honey, maple syrup or fruit and vegetables still contain sucrose, glucose and fructose, so in that respect they are not much different to table sugar.
Of all of them, using whole fruit and vegetables as sweeteners seems to me the most preferable because, not only are they ‘real foods’, but there are also many added benefits. This is why I have based most of the recipes in this book around fruit and vegetables.
Fruit and vegetables, whether fresh or dried, almost all contain some level of sugar, be it sucrose, glucose, fructose or all three. Some fruits
- and especially dried fruits like dates or raisins - can be considered high-sugar foods and therefore you need to watch how much you eat.
However, they offer many added benefits, such as fibre and an assortment of vitamins and minerals. Large amounts of fibre help you to feel full, which should support portion control.
Where a little extra sweetness is required, I have used small quantities of stevia because it is naturally derived and does not cause tooth decay, but feel free to substitute it with a different sweetener if you prefer.
What is stevia?
Stevia rebaudiana is a plant with white flowers found in Brazil and Paraguay. Its leaves contain a cocktail of related chemicals called steviol glycosides (including steviosides and rebaudiosides), which have a sweetness over 200 times stronger than sucrose. It also has a slightly bitter aftertaste, which can be unpleasant. Stevia extracts are poorly metabolized, passing through the stomach and small intestine intact. Bacteria in the large intestine then break the molecules down.
The stevia you can buy usually involves a refined extract of the leaf, blended with another sugar substitute to bulk it out and improve the flavour. Though sweetening agents in stevia leaves have no GI, no calories and don’t cause tooth decay, the bulking product may do, so check the label carefully.
Stevia extracts have been in use as a sweetener in Japan and other Asian countries for decades. In the European Union, stevia-based sweeteners were approved in 2011. Currently, the Food and Drug Administration (FDA) in the USA has not approved the whole leaf or crude extracts for use in food - only sweeteners using rebaudioside A have been accepted as GRAS (Generally Recognized As Safe). For more information, see www.fda.gov. Also, see for more about my use of stevia.
