Sugar.... what is it, and why the big deal?
There are three important simple sugars:
Glucose, Fructose and Galactose, all other sugars are a combination of these.
Sucrose = Glucose + Fructose = Table Sugar
Lactose = Glucose + Galactose = Milk Sugar
Maltose = Two Glucose molecules joined together in an unusual way = Sugar found in Beer
(Sweet Poison - David Gillespie)
So what does this mean?
These sugars are the carbohydrates found in food + fibre (cellulose) which we don't use for energy. So a carbohydrate is just sugar + fibre - complex carbohydrates have a higher fibre content and simple carbohydrates consist mainly of sugar. When eaten together, sugar + fibre will make us feel full and satisfied.
The glucose half of sucrose increases blood sugar levels and therefore insulin. When insulin is raised your body is prompted to burn glucose as energy and store any excess as fat in order to normalise blood sugar levels. Every cell in your body can metabolise glucose and use it for energy however only your liver has the ability to metabolise the fructose half of sucrose.
Fructose has minimal effect on insulin production which makes it low GI and therefore it has been promoted as a good sugar for diabetics to consume as it won't raise blood sugar levels. However there are problems that arise from excessive consumption of fructose:
Fructose problem 1:
Fructose is often used as a sweetener because it is much sweeter than glucose and easy to produce (in the form of High Fructose Corn Syrup). Take the fibre away from fructose (ie. the skin and flesh of the fruit) and your body has no method of telling when you have had enough - Fructose does not act on your fullness hormones. Therefore you can consume large amounts of fruit juice with a meal and your body will not register this as making you full.
Fructose problem 2:
Every cell in your body can metabolise glucose and use it for energy however only your liver has the ability to metabolise fructose by converting it to fatty acids and storing it as visceral fat (the fat surrounding your organs). All the fructose you consume is converted to FAT.
Fructose eaten in moderation and in season as nature intended ie. with all the fibre, skin and nutrients contained in the WHOLE fruit won't cause too many problems. The issues arise when we take 10 apples, juice them and then consume them as a 'healthy' beverage. Or consume products that use fructose as a sweetener.
Many weight loss bars/products contain fructose as a sweetener, it is a cheap way to make something tasty and it won't spike your insulin - therefore they can boast of a Low GI Rating. What they don't tell you is that the fructose you are consuming will still be stored as fat.
So what about Natural sweeteners?
This is where I have a big gripe! There are soo many recipes out there that advocate the use of large quantities of natural sugars to replace the same amount of refined sugar (honey, dried fruit, maple syrup, rice malt syrup, coconut sugar, agave etc). The problem being that your body still meatbolises it the same - you may be getting a few extra nutrients from the natural sugar but it will still spike your insulin and promote you store fat and the fructose component will still be converted straight to fatty acids and be stored around your organs! Stevia is one natural sweetener that has no effect on blood sugar levels. Used in its powdered form it is VERY sweet and not very nice if you use too much - this forces you to use it in moderation!
What do we do then?
I believe that natural sweeteners (with the exception of agave - which is up to 90% fructose) are fine used in moderation, but replacing 2tsp of sugar with 2tsp of honey in your tea is not moderation!! The point is to get used to food not being so sweet. We train our children from a young age (or reinforce an inbuilt love for everything sweet) by giving them lollies for treats, sweet cereal for breakfast, bickies and museli bars in lunch boxes, fizzy drinks and icecream. Sugar, until recently, has not been not identified as something to be wary of - fat is the enemy according to the Heart Foundation so we get rid of the fat, products become tasteless and sugar is added. The more sugar you consume, the more you will want! We need to learn to enjoy food without it being super sweet and we need to start educating our kids NOW!