Feedback—Your FAQs Answered

My husband and I are following the 12-week Action Plan in The Low GI Diet. However, I am currently breastfeeding and I wonder whether you need to eat a little more than usual to allow for lactation or pregnancy?
Increased energy intake is recommended during pregnancy and lactation. The greatest requirement is for lactation—add 2000 kJ (500kcal) to daily requirements. In early pregnancy there is no greater need but by the 3rd trimester an extra 2000 kJ (500kcal) are recommended daily. This is based on a normal/healthy pre-existing body weight. If you are already overweight then you wouldn't need to increase by so much.
Estimations of energy requirement should always be taken as a guide only. Differences between people can be enormous. Often it is more realistic to use appetite as a guide to whether you are eating enough.


The increased calories can come from any source (carbohydrate, protein or fat) but it is safest to increase calories from carbohydrate or protein if you are unsure about amounts, because these nutrients have the greatest effect on satiety.

I haven't been able to find a reference as to what GI number a person should shoot for when trying to diet. Is there a formula, such as "take goal weight, multiply by age, divide by activity level?
The simple answer is no, there’s no formula. You don’t need to add up the GI each day. In fact there’s no counting at all as there is with calories/kilojoules. The basic technique for eating the low GI way is simply ‘This For That’: swapping the high GI carbs in your diet with low GI foods. This could mean eating muesli at breakfast instead of wheat flakes, low GI bread instead of normal white or wholemeal bread, or a sparkling apple juice in place of a soft drink. So, what you need ‘to shoot for’ is identifying the high GI carbs in your current diet and swapping them for some quality low GI carbs. Dietitian Kaye Foster-Powell says in Low GI Eating Made Easy: ‘We have found that many people who substitute low for high GI foods in their everyday meals and snacks reduce the overall GI of their diet, gain better blood glucose control and lose weight.

Kaye Foster-Powell

If you are looking for some guidelines, here’s how she answers the ‘what do I eat’ question. Every day you need to:
I’m confused. What’s the difference between GI and GL? Should I use GI or GL and does it really matter?
Your blood glucose rises and falls when you eat a food or meal containing carbohydrate. How high it rises and how long it remains high depends on the quality of the carbohydrate (its glycemic index value or GI) as well as the quantity of carbohydrate in your meal. Researchers at Harvard University came up with a term that combines these two factors—glycemic load (GL). Some people think that GL should be used instead of GI when comparing foods because it reflects the glycemic impact of both the quantity and quality of carbohydrate in a food. But more often than not, it’s low GI not low GL that predicts good health outcomes. So which one should you use?

We are often asked this question. Our advice is to stick with the GI rather than GL—the reason being that following the low glycemic load (GL) route can lead you straight to a low carb diet: ie fatty meats and butter, for example have a low GL. .
But if you eat plenty of low GI foods, you’ll find that you are automatically reducing the GL of your diet and at the same time you’ll feel fuller for longer with these satisfying carbohydrate-containing foods, as well as improve many health parameters.

We also emphasise that there’s no need to get overly technical about this. Think of the GI as a tool allowing you to choose one food over another in the same food group—the best bread to choose, the best cereal to choose etc.—and don’t get bogged down with figures. A low GI diet is about eating a wide variety of healthy foods that fuel our bodies best—on the whole these are the less processed and wholesome foods that will provide carbs in a slow release form.
The take-home message:
How do you figure out the GL numbers?
Glycemic load is calculated simply by multiplying the GI of a food by the amount of carbohydrate in the portion (in grams) you are eating and dividing by 100. Here’s how
Glycemic load = (GI x carbohydrate per serving) ÷ 100
Let’s say you wanted to have an apple for a snack. Apples have a GI of 40 and 1 medium apple contains 15 grams of carbohydrate.
So, the glycemic load of your apple snack is (40 x 15) ÷ 100 = 6.
If you were very hungry and tucked into 2 apples you be eating 30 grams of carbs and the GL of your snack would be 12. The GI doesn’t change, but you are eating more carbs because you are eating 2 apples.


Does Low Carb automatically mean low GI?
Not at all. Here’s why. Low carb is just about quantity; it simply means that a food or meal does not contain much carbohydrate at all. It says nothing about the quality of the carbs in the food or meal on your plate. You could be eating a low carb meal but the carbs have a medium or high GI. Low GI on the other hand is all about quality.

Photo: Ian Hofstetter, The Low GI Diet Cookbook

Whether you are a moderate or high carb eater, low GI carbs (wholegrain breads, legumes /pulses, many fruits and vegetables) will have significant health benefits—promoting weight control, reducing your blood and insulin levels throughout the day, and increasing your sense of feeling full and satisfied after eating. We suggest that you make the most of quality carbs and reap the add-on health benefits such as: