Bicycle Network Victoria: Health Matters

Not all carbohydrates are equal. Some carbohydrate foods will maintain energy for hours, while others give you a rapid but less sustained energy boost. The type of carbohydrate you eat may also affect feelings of fullness and this can influence appetite and the amount of food you eat. Understanding glycemic index will help you to make smart carbohydrate choices.

What is the glycemic index?

The glycemic index (GI) ranks carbohydrate foods according to their effect on blood glucose levels. The GI of a particular food indicates the rate of digestion and absorption. Foods are given a ranking of between 0 and 100 according to the specific blood glucose response.

• Low glycemic index <55
• Moderate glycemic index 55–70
• High glycemic index >70

Foods with a high GI are absorbed quickly and cause a rapid rise in blood glucose levels. Foods with a low GI are broken down more slowly and keep blood glucose levels more stable.

Maintaining glucose levels

Glucose is the preferred fuel for our brain and muscles. If our blood glucose levels get too low (hypoglycaemia) we lack fuel and this can make us feel tired, dizzy and generally unwell. However, if blood glucose levels rise too quickly this is often followed by a large drop which can lead to reduced energy levels and cravings for sugar.
Maintaining steady blood glucose levels helps the brain and muscles keep performing well. Factors that improve blood glucose control include:

• Maintaining a healthy body weight and body fat levels
• Physical exercise
• Adequate carbohydrate intake spaced throughout the day
• Slow release of carbohydrate into the bloodstream

Benefits of low GI foods

Choosing low GI foods in meals and snacks will help slow the release of carbohydrate into the bloodstream. Other reasons to eat low GI foods include:

• Stable blood sugar levels can help to control hunger and cravings
• Most low GI foods are rich in important vitamins, minerals and fibre
• A low GI diet may help to improve the balance of fats in the blood
• Low GI foods are very important for diabetics who need to control blood glucose by spacing carbohydrate intake throughout the day.

Just because a food has a low glycemic index, this does not mean you can eat as much as you like! Low GI foods can still be high in total carbohydrate, so intake should be appropriate for the amount of carbohydrate you burn over the day.

Don’t skip breakfast

We all know the feeling of the mid-afternoon slump, where you could easily curl up for a nap or reach for the coffee and chocolate or biscuit to keep going. Making smart carb choices early in the day can prevent fatigue later on. If you ride to work, you should eat before you leave to keep energy levels up and prevent mid-morning hunger.

Low GI breakfast ideas

• Wholegrain cereal with low-fat milk, chopped fruit
• Porridge with stewed apple and cinnamon
• Multi-grain toast with avocado and sliced tomato
• Natural muesli, Tinned fruit (in natural juice), Low-fat fruit yoghurt
• Banana soymilk smoothie
• Multi-grain toast with baked beans

Lisa Sutherland, is a sports dietician and fitness consultant who works for the Hawthorn Football Club and the Victorian Institute of Sport – 0414 574 678, www.lisasutherland.com.

This article first appeared in the October-November 2005 Issue of Ride On.

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