Carbohydrates are an essential part of the diet, but are you trying to lose weight and confused about which ones are good for you? Nutritionist Kathleen Alleaume has the low down.
For many years, we’ve been told to eat a “low fat” diet and eat more carbohydrates. But now with an ever growing epidemic of obesity and diabetes, we’re now told to be more careful about the type and amount of carbs we eat. So how do you know which is which? The answer is both simple – and complex.
Not all carbs are created equal
We use to categorise carbs into simple or complex. Simple carbs (aka sugars) are found in fruit sugar (fructose), milk sugar (lactose) and table sugar (sucrose), and complex carbs (aka starches) are found naturally in bread, rice and pasta, noodles, legumes, corn and potatoes.
Dividing carbohydrates into ‘simple’ and ‘complex’ made perfect sense on a chemical level. But it didn’t do much to explain what happens to different kinds of carbohydrates inside the body. For example, the starch in white bread and white potatoes converts this starch to blood sugar nearly as fast as honey, chocolate, ice-cream and some fruits, which explains why we no longer classify carbohydrates as ‘simple’ or ‘complex’. Instead we now say “low” or “high” GI (glycemic indix) carbs.
What does the GI mean?
The GI is a way of comparing different carbs by ranking their effect on blood sugar levels. High GI carbs cause a rapid rise and decline in blood sugars, whereas low GI carbs are the ones that produce only small fluctuations in our blood sugar and insulin levels - the secret to reducing your risk of heart disease and diabetes, and is the key to sustainable weight loss.
Are Carbohydrates Fattening?
Carbohydrates do not make you fat. Eating too much food makes you fat. If you eat more kilojoules than you use, you will put on weight whether those kilojoules came from fats, carbohydrates or proteins. Even if the food has a low GI (ahem chocolate and ice-cream), it doesn't mean you can eat as much as you like. So, portion size and moderation matters, a lot!
What about Low-fat Foods?
Who hasn’t gone for the extra scoop of ice-cream and assumed it is a license to binge because it’s “low-fat?” The overemphasis on reducing fat caused the consumption of refined carbohydrates and sugar in our diets to soar. The problem is, food labeled “fat-free” and “low-fat” are not necessarily void of kilojoules.
Some low-fat yoghurts have so much sugar they can be more fattening than full-fat. For example, serve of unsweetened plain full-fat yoghurt has about two teaspoons of sugar (lactose) from the milk, compared to five or more teaspoons of table sugar (sucrose) added many flavoured low-fat yoghurts. Be warned: compare labels before you buy.
Make the Switch
Lowering the GI of your diet is as simple as swapping a high GI food for a lower GI alternative. Here’s how-
High GI Low GI
Mash potato - Mash sweet potato or pumpkin or puree legumes or white beans
Jasmine Rice - Basmati or Doongoora rice
White bread - Wholegrain bread: rye, soy and linseed, spelt, multigrain
Juice - Whole piece of fruit
Rice crackers - Rye crispbread
Confectionary - Dried fruit
Rice pasta - Durum wheat pasta or noodles
Kathleen Alleaume is an Exercise Physiologist and Nutrition, and the founder of The Right Balance www.therightbalance.com.au