NATASHA THIELE, REPORTER: You just need to open the pantry and take a closer look to see that sugar is found in a lot of the food we eat! It's even in stuff you may not realise! But what is it about sugar that makes it a popular ingredient? Let's find out.
Sugar is a carbohydrate, which our body needs for energy. It also makes things taste better. It helps thicken food products and it can act as a preservative to make foods last longer. So it's added to a lot of processed food.
PROFESSOR ROBERT LUSTIG, UNIVERSITY OF CALIFORNIA: One half of the sugar that we are consuming today is in items that we didn't even know had sugar. Tomato sauce, barbecue sauce, hamburger buns, hamburger meat. All sorts of processed foods. If you look at virtually every item in the store that has a food label, it has some form of sugar.
But some people are worried sugar can have an impact on our health if we have too much of it. In the 1970s there was a rise in obesity and diabetes. Health experts said there was too much fat in people's diets. That's when low-fat products hit our shelves! But the problem with low-fat food was, it didn't always taste that good. So they added sugar.
REPORTER: A little bit of mayonnaise on a sandwich makes it taste nice right? Well, take a look at this. Whole-fat mayonnaise has just over 2 percent sugar. Whereas the low-fat version has 13 percent that's more than six times the amount!
Some people reckon that the extra sugar that's replaced fat is doing more harm than good. And it could be making more people overweight. Researchers also say too much sugar can lead to other problems like heart disease and dementia. Some reckon sugar's so bad for you it should be taxed, just like tobacco and alcohol.
But not everyone agrees. Some people in the sugar industry say there's no evidence to prove that sugar isn't good. They say that like any other food, sugar is an important part of a balanced diet.
REPORTER: But it's important to know how much to eat. It's recommended that kids have no more than two teaspoons of sugar a day. That's this much. But a can of soft drink has around five times that that amount.
Here in Australia there are new campaigns, encouraging people to think twice before having things like sugary drinks. And to be aware of the sugar that's hiding in places where you might not expect it.