1 October 2006

Feedback—Your FAQs Answered

I have gestational diabetes. What should I choose from the menu at my local Asian restaurant to stick to my daily food guide for carb serves – a noodle soup with rice noodles; a dish with rice noodles (thick or thin); a dish with Hokkien (egg) noodles; or a dish with boiled rice?
The noodle soup is probably best as the noodles are low GI and the amount in a soup should fit into your recommended carb serves per meal. The other noodle dishes are also low GI, but will probably have a larger quantity of noodles, so you would need to limit the amount of these you eat and combine them with some vegetables. Or you could ask the restaurant proprietor to make you a noodle dish with half the amount of noodles as usual and to fill the rest of the plate with vegetables. In an Asian restaurant, the rice is likely to be Jasmine, long grain or calrose – all of which are high GI, so it is best to limit this. If you were choosing rice, keep the portion small, and again fill your plate with lots of vegetables.

[PREGNANT LADY]

I love to bake, but want to reduce the GI of the products? Here are my questions – all seven of them!

  1. Can I estimate the GI/GL for baked goods?
    Estimating the GI of baked goods is not an accurate science by any means. There are too many variables that can affect the resultant GI and GL. It is always best to test baked goods. However we can make general assumptions – such as replacing flour with lower GI ingredients such as oats, dried fruit, oat bran and so on. Estimating a final GI would only ever be a rough estimate however.

  2. Since spelt flour hasn’t been GI tested, can I estimate its GI value?
    No we can’t estimate it and given the reported health properties of this grain (it is a variety of wheat) it would be nice to have it tested. It does have a higher protein content than plain or all-purpose wheat flour and this may make a difference, although not necessarily. With the present information we could only play conservatively and give it the same GI as plain or all-purpose wheat flour – but emphasise the other nutritional qualities of spelt.

  3. Flax seed and oat bran are said to lower GI, what proportion is necessary to get a lowering effect?
    To get a GI lowering effect the flaxseed or oat bran would need to replace some of the flour – the extra soluble fibre is what really has an effect on the GI. It’s difficult to put an absolute value on how much but we would estimate as least 10% in order to have a realistic effect on the GI. You need to weigh up how much can be added without negatively affecting the taste of the end product.

  4. Ingredients like almonds, sunflower seeds, soy protein, eggs, butter – are they just ‘bulk’ that will ‘dilute’ the GI/GL per gram of finished product? Or will they have actual effect on GI?
    None of these ingredients contain an appreciable amount of carbohydrate and so do not have a GI themselves and neither will they affect the GI of the end product. They will however affect the GL since they alter the gram weight of the finished cookie…in other words more fat and protein will reduce the amount of carbohydrate per gram of cookie.

  5. Is brown sugar the same as regular sucrose?
    Yes – although marginally less carbohydrate per 100 grams than white sugar any effect on GL will be minimal. Brown sugar is just sucrose with some of the molasses still present.

  6. Is there a GI value for molasses?
    No – but it is unlikely to be very different from sucrose since it is predominantly sucrose, with some fructose and glucose also present. It does however contain less carbohydrate per 100g than brown or white sugar and so the contribution to the overall GI and GL of the product will be affected if molasses replaces some of the sugar in the original recipe. There are of course a few extra minerals found in molasses too.

  7. I use fructose in my baking when it’s doable, but right now there is a lot of debate about fructose and it’s being described as the really bad guy.
    Fructose is a refined carbohydrate, and as such we recommend using it in moderation – 1–2 teaspoons in a cup of tea or coffee, and up to about a ½ cup as a sweetening substitute for sugar in recipes. After this we would start recommending you opt for a non-nutritive sweetener, especially if you had diabetes.
I have recently been diagnosed with irritable bowel disease and am interested to know if following a low GI diet would be recommended to help control my symptoms. I am also trying to lose weight.
A low GI diet could certainly help you with weight loss, but IBS is very individualised when it comes to diet. It would be best to see an Accredited Practising or Registered Dietitian who could help to design an eating plan to help with both your IBS symptoms and with losing weight.


Look it up in our A–Z: The GI Glossary (continued)

[GLOSSARY]

Starches are long chains of sugar molecules. They are called polysaccharides (poly meaning many). They are not sweet-tasting. There are two sorts – amylose and amylopectin.

Amylose is a straight-chain molecule, like a string of beads. These tend to line up in rows and form tight compact clumps that are harder to gelatinise and therefore digest.

Amylopectin is a string of glucose molecules with lots of branching points, such as you see in some types of seaweed. Amylopectin molecules are larger and more open and the starch is easier to gelatinise and digest.

Starch gelatinisation is what happens when starch granules have swollen and burst during cooking – the starch is said to be fully gelatinised. The starch in raw food is stored in hard, compact granules that make it difficult to digest. Most starchy foods need to be cooked for this reason. During cooking, water and heat expand the starch granules to different degrees; some granules actually burst and free the individual starch molecules. The swollen granules and free starch molecules are very easy to digest because the starch-digesting enzymes in the small intestine have a greater surface area to attack. A food containing starch that is fully gelatinised will therefore have a very high GI value.

Stevia (Stevia rebaudiana), native to South America, first came to the attention of the Western world in the 1800s, but remained relatively obscure until it was used as an alternative sweetener in the UK during the Second World War. It’s not widely available. The leaves of this semi-tropical herb of the aster family are around 30 times sweeter than cane sugar but with no kilojoules (calories). As a herb, the leaves can be used fresh or dried. In the dried form less than 2 tablespoons of crushed leaves can replace a cup of sugar, although it's hard to be specific as actual sweetness can vary. Stevioside, its extract, is 250–300 times sweeter than sucrose and is not approved for use as a food in Australia but is listed as a ‘therapeutic good’ with the Therapeutic Goods Administration.

Sugars are a type of carbohydrate. The simplest is a single-sugar molecule called a monosaccharide (mono meaning one, saccharide meaning sweet). Glucose is a monosaccharide that occurs in food (as glucose itself and as the building block of starch). If two monosaccharides are joined together, the result is a disaccharide (di meaning two). Sucrose, or common table sugar, is a disaccharide, as is lactose, the sugar in milk. As the number of monosaccharides in the chain increases, the carbohydrate becomes less sweet. Maltodextrins are oligosaccharides (oligo meaning a few) that are 5 or 6 glucose residues long and commonly used as a food ingredient. They taste only faintly sweet. Sugars found in food:

Monosaccharides (single-sugar molecules)
glucose
fructose
galactose

Disaccharides (two single-sugar molecules)
maltose = glucose + glucose
sucrose = glucose + fructose
lactose = glucose + galactose

Triglycerides also known as triacylglycerols or blood fats are another type of fat linked with increased risk of heart disease. Having too much triglyceride often goes hand in hand with having too little HDL cholesterol. Having high levels of triglycerides can be inherited, but it’s most often associated with being overweight or obese. Normal ranges for triglycerides are 1.0–2.3 mmol/L, people with diabetes should aim to keep their triglyceride levels under 2.0 mmol/L as they are at greater risk of cardiovascular disease.

7 comments:

Anonymous said...

I've read the info about gelatinized starches and an wondering if a low GI meal such as a vegetable stir-fry with a sauce thickenend with cornstarch (gelatinised in appearence) should be considered high GI.

Thanks

Anonymous said...

In response to question number 4 of your October FAQs, you say that the addition of almond meal, eggs, butter etc won't affect the GI of a bakery product. However, in previous newsletters you say that adding fat and protein to a carbohydrate-containing food can reduce the GI of that food. Would the addition of butter and/or eggs provide enough fat to reduce the glycaemic effect of the flour? Many recipes contain more than 60 g of butter and 2 or more eggs.

Anonymous said...

According to Dr. Deihl, DrHSc, MPH, and founder of the CHIP program (Cardiac Health Improvement Project) fats can inhibit the effectiveness of insulin in the bloodstream for Type II (or non-insulin dependent) diabetes. Adding fiber to your diet will conversely slow the digestion and absorbtion of calories and provide a lower GI for your meal. Ref: "Dynamic Living" and "Reversing Disease with Fork & Knife". The first book should be available via bookstores.

Anonymous said...

We covered cornstarch and other thickeners in Feedback in August 2006. Essentially, the amount of cornstarch in a stir fry is very small and is unlikely to affect the GI significantly. What's more important is to serve your stir fry with a moderate portion of low GI noodles or a low or lower GI rice. Dietitian Kate Marsh also suggests adding chickpeas to a stir fry to reduce the overall GI of a meal.

Anonymous said...

As we say upfront, estimating the GI of baked goods isn't an exact science and it's really best to test - it is impossible to guesstimate the GI-lowering effect of say eggs and butter when baking a cake or cookies. That's why we always recommend that if people want to reduce the GI of baking or making desserts, they replace some of the high GI ingredients with those that we know have a low GI (like rolled oats and dried fruit). In addition, our message is that the GI is a tool to be used in the context of an overall healthy diet. That's why we don't recommend reducing the GI by adding an ingredient high in saturated fat like butter.

Anonymous said...

cna you please tell me the gi of brown rice syrup?

Anonymous said...

Brown rice syrup has not been glycemic index tested at this stage. If you are looking for ways to sweeten foods without using table sugar, you might like to try using pure maple syrup (GI 54), a pure floral honey (the Australian ones tested had a GI ranging from 35 to 55) or Sweet Cactus Farms Agave Nectar (GI 19).