Q. Is sugar absorbed more rapidly than starchy foods?

Written by Catherine Saxelby on Friday, 14 February 2014.
Tagged: GI, glycemic index, healthy eating, lentils, sugar

Q. Is sugar absorbed more rapidly than starchy foods?

A. It all depends on which type of starchy food you're comparing sugar to. We used to think that starches were long ‘complex' molecules that took longer to be broken down by the body. Sugar was viewed as ‘simple' and considered to be easy and quick to digest and absorb. Now, thanks to years of research about the Glycaemic index or GI, we realise this view of simple vs complex is over simplified.

Although all carbohydrate foods are ultimately broken down to sugars (glucose, fructose), their effect on the body's blood own glucose levels varies quite significantly from food to food.

This is largely influenced by:

  • the type of starch in the carbohydrate e.g. amylopectin takes longer to be digested than amylose
  • how processed or cooked the food is and
  • whether there is any fat or fibre accompanying the carbohydrate.

Compare 6 GI values, from high to low GI

Potato, mashed 91 High GI
Jasmine white rice 89 High GI
White sliced bread 80 High GI
     
Spaghetti 44 Low GI
Burgen bread, wholemeal with seeds  39     Low GI
Baked beans   37 Low GI
FOR COMPARISON:    
Sugar 68 Medium GI

Remember that the GI is a measure of the
quality of the carbohydrate and
how slowly or quickly it's absorbed.

From the figures, you can see that some starchy foods (potato, rice, white bread) have a high GI over 70 and so are absorbed much faster than sugar.

While other starches (pasta, grainy bread a and legumes) which have a low GI under 55 take longer to get into the system.

So it's hard to generalise. The important thing to take home is that sugar has a medium GI so it's absorbed slower than potatoes or white bread or white rice but not as slowly as beans or pasta.

This is not permission to overdo the sugar - it's still a low-nutrient food that should be used sparingly, just enough to sweeten and that's all.

Catherine Saxelby

About the Author

Catherine Saxelby knows nutrition! She is an accredited nutritionist, food commentator, blogger and award-winning author. Her latest book Catherine Saxelby's Food and Nutrition Companion answers all those tricky questions on healthy eating, diets and supplements. It draws together a lifetime of advice and gives you all you need to know to eat right! It's a complete A to Z. A handy desk go-to reference.