GI Index and what is it

I'd first like to thank everyone for their kind comments, especially from all the new people who have visited my blog. My main use for this blog is to have a record of my feelings, my ups and downs of life and my weight loss journey. I must admit that I do forget that others can and do come across my blog and read it, let alone that it inspires other people.

I received a really lovely post from Andrea from Germany regarding how inspiring my blog was, and how this has encouraged her to start her own blog in German. Hope this doesn't embarrass you Andrea but your comments really got me thinking about how many people can and do read this blog (and don't comment so I don't realise people read it) and how it affects peoples lives.

Andrea also inspired this post when she asked me "What is GI diet, or what is GI and can you point me to more information (or write a blog entry, *smile*) on what a low GI diet is? " Andrea I hope I can answer your questions adequately.

I got the information below from a website http://www.glycemicindex.com/

What is Glycemic Index (GI)

The glycemic index (GI) is a ranking of carbohydrates on a scale from 0 to 100 according to the extent to which they raise blood sugar levels after eating. Foods with a high GI are those which are rapidly digested and absorbed and result in marked fluctuations in blood sugar levels. Low-GI foods, by virtue of their slow digestion and absorption, produce gradual rises in blood sugar and insulin levels, and have proven benefits for health. Low GI diets have been shown to improve both glucose and lipid levels in people with diabetes (type 1 and type 2). They have benefits for weight control because they help control appetite and delay hunger. Low GI diets also reduce insulin levels and insulin resistance.

Recent studies from Harvard School of Public Health indicate that the risks of diseases such as type 2 diabetes and coronary heart disease are strongly related to the GI of the overall diet. In 1999, the World Health Organisation (WHO) and Food and Agriculture Organisation (FAO) recommended that people in industrialised countries base their diets on low-GI foods in order to prevent the most common diseases of affluence, such as coronary heart disease, diabetes and obesity.

There is a really good book available called "The Low GI Diet which includes a 12 week action plan". This book is published by Prof Jennie Brand-Miller, Kaye Foster-Powell and Dr Joanna McMillan Price.

What are the Benefits of the Glycemic Index?

Eating a lot of high GI foods can be detrimental to your health because it pushes your body to extremes. This is especially true if you are overweight and sedentary. Switching to eating mainly low GI carbs that slowly trickle glucose into your blood stream keeps your energy levels balanced and means you will feel fuller for longer between meals.

• Low GI diets help people lose and control weight
• Low GI diets increase the body's sensitivity to insulin
• Low GI carbs improve diabetes control
• Low GI carbs reduce the risk of heart disease
• Low GI carbs reduce blood cholesterol levels
• Low GI carbs can help you manage the symptoms of PCOS
• Low GI carbs reduce hunger and keep you fuller for longer
• Low GI carbs prolong physical endurance
• High GI carbs help re-fuel carbohydrate stores after exercise

How to Switch to a Low GI Diet

The basic technique for eating the low GI way is simply a "this for that" approach - ie, swapping high GI carbs for low GI carbs. You don't need to count numbers or do any sort of mental arithmetic to make sure you are eating a healthy, low GI diet.

• Use breakfast cereals based on oats, barley and bran
• Use breads with whole grains, stone-ground flour, sour dough
• Reduce the amount of potatoes you eat
• Enjoy all other types of fruit and vegetables
• Use Basmati or Doongara rice
• Enjoy pasta, noodles, quinoa
• Eat plenty of salad vegetables with a vinaigrette dressing

Sydney University Glycemic Index Research Service (SUGiRS)

Sydney University GI Research Service (SUGiRS) was established in 1995 to provide a reliable commercial GI testing laboratory for the local and international food industry. Foods are tested in healthy volunteers according to standardised methods that have been validated against laboratories overseas. Insulin, satiety, hunger and other parameters can be assessed simultaneously. SUGiRS has an established reputation for quality, speed and flexibiltiy. We can work with your company to develop new low GI products or help lower the GI of existing ones. Foods that meet nutrition guidelines and have been GI tested can carry the GI symbol. Your results are strictly confidential and are your property. Data are released for publication only with your written approval.

How is the GI measured?

The glycemic index (GI) is a measure of the power of foods (or specifically the carbohydrate in a food) to raise blood sugar (glucose) levels after being eaten. The GI values of foods must be measured using valid scientific methods. It cannot be guessed by looking at the composition of the food. Currently, only a few nutrition research groups around the world provide a legitimate testing service. Professor Jennie Brand-Miller at the Human Nutrition Unit, Sydney University has been at the forefront of glycemic index research for over a decade, and her research group has determined the GI values of more than 400 foods.

The GI value of a food is determined by feeding 10 or more healthy people a portion of the food containing 50 grams of digestible (available) carbohydrate and then measuring the effect on their blood glucose levels over the next two hours. For each person, the area under their two-hour blood glucose response (glucose AUC) for this food is then measured. On another occasion, the same 10 people consume an equal-carbohydrate portion of glucose sugar (the reference food) and their two-hour blood glucose response is also measured. A GI value for the test food is then calculated for each person by dividing their glucose AUC for the test food by their glucose AUC for the reference food. The final GI value for the test food is the average GI value for the 10 people.

Foods with a high GI score contain rapidly digested carbohydrate, which produces a large rapid rise and fall in the level of blood glucose. In contrast, foods with a low GI score contain slowly digested carbohydrate, which produces a gradual, relatively low rise in the level of blood glucose.

The following information is from the website http://health.ninemsn.com.au/article.aspx?id=101083

How to follow a Low Gi Diet.
Make an Internet search for any fad diet and you are likely to get as many hits claiming it is nonsense as those claiming it revolutionises weight loss. But, here's the thing about low-GI; it's not a fad and there are no medical journal articles or scientific studies that say it isn't a healthy dietary concept. Eating low-GI is a key nutrition message that goes hand-in-hand with other healthy eating guidelines such as eat less saturated fats and eat more fruit and vegetables.

The Glycemic Index (GI) was devised about 20 years ago when researchers looked closer at the dietary recommendations for diabetics; which was to eat more complex carbohydrates (starch) because they took longer to process and digest than simple carbohydrates (sugar). What the researchers discovered was that the effect of a carbohydrate on blood-glucose levels was not determined by the sugar or starch. For example, we now know that the effect chocolate has on blood-glucose is actually lower than potatoes. That doesn't mean chocolate is healthy — but I'll get to that later.

"GI is a ranking (from 1 to 100) which measures the effect of a food on your blood-glucose level over the two hours after the food is eaten," explains Joanna McMillan-Price, a Sydney nutrition scientist and co-author of The Low GI Diet book.

"You get a bell-shaped curve when you eat food containing carbohydrates; the blood-glucose rises and as your body produces insulin it pushes the glucose out of the blood and into tissues, and then you see the blood-glucose level falling." McMillan-Price explains that when eating high GI foods, you get a very high bell curve response with a dramatic drop. With a low-GI food, there is a slower and steadier rise in the blood-glucose level.

RELATED LINKS

• The GI diet makes a come back

How does low-GI promote better health?
"Research has shown that very high glucose levels after meals, called glucose spikes, are damaging to our arteries and various blood vessels, and they promote far too much insulin to be around," explains McMillan-Price.

Eating low-GI foods means you avoid those spikes and dramatic falls in blood-glucose so you get a much steadier stream of energy. You, therefore, reduce your risk of heart disease and other chronic diseases that are implicated by those blood-glucose fluctuations.

How low-GI contributes to weight control
High GI foods are bad for weight control for two reasons, says McMillan-Price. Firstly, the glucose spikes stimulate hunger because you are getting that dramatic drop in glucose, 90 minutes to two hours after eating. By eating low GI foods you feel fuller for longer and are, therefore, not as likely to go searching for snacks every two hours.

Secondly, insulin is a storage hormone that stockpiles nutrients for later use by the body. A high-GI diet causes a lot of insulin to be produced and when you have too much insulin in your body too much of the time, it makes it easier to store fat and harder to burn it.

Applying the low-GI concept to your diet
McMillan-Price says the recommendation is that at least two meals a day should be accompanied by a low-GI food. "It doesn't mean you should never eat high-GI foods, but preferably put most meals together with a low GI food," she says.

However, don't be worried into thinking you need to know the GI value of every food. Healthy foods such as fruits and vegetables, except potatoes, should be eaten daily regardless of their GI. Simply knowing the low, medium and high varieties of the major carbohydrate foods in your diet — breakfast cereals, breads, rice, pasta — and choosing the low-GI ones is sufficient to produce healthy benefits.

If you simply can't go without certain high GI favourites occasionally, like jasmine rice, serve just a small portion and add a low GI alternative, like a lentil dahl. It is also worth considering the content of your plate. Half your plate should be vegetables, and the other half split into two quarters containing protein and low GI carbohydrate.

Now, getting back to the low GI of chocolate, just because something has a low GI doesn't mean you should indulge, says McMillan-Price. "Low-GI has been misunderstood by some people who think it is the be all and end all," she says. "Don't use the GI as the first step in choosing what foods you should be eating. The GI should come after you've looked at whether something is a good food that has low levels of saturated fat and is nutrient-rich … and then the GI becomes a tool to choose which is the best carbohydrate from these sources."

So, it's not necessary to know the GI of a chocolate bar because it's clearly an energy-dense food without many nutrients that is not going to aid weight loss.

What is the GI symbol?
Foods carrying the GI symbol must meet specific nutritional criteria and have their GI measured using the approved method. The program, designed to help consumers choose low-GI foods, is run by the non-profit company Glycemic Index Ltd, whose members are the University of Sydney, Diabetes Australia and the Juvenile Diabetes Research Foundation.

Glycemic Index Ltd explains that when you see the GI Symbol on a food label, you will find the GI value near the nutrition information panel along with the words 'high', 'medium' or 'low'. You will also know that the food meets the program's nutritional criteria, which generally means it is a good nutritional choice for that food group.

The GI table

High — 70 or more, Medium — 56 to 69 inclusive, Low — 55 or less
Instead of ...	Try ...
Long-grain white Jasmine rice (109)	Ricegrowers Doongara white rice (55), Mahatma long-grain white rice (50)
Buttercup Wonder White bread (80)	Burgen Oat Bran and Honey bread (49), Tip Top 9 grain bread (43)
Ricegrowers, brown rice pasta (92)	White capellini pasta (45), egg fettuccine (40)
Dried rice noodles (61)	Fresh rice noodles (40), soba noodles (46)
Skippy cornflakes (93)	All Bran Fruit and Oats (39), Kelloggs Guardian (37)
Uncle Tobys instant porridge (82)	Regular porridge (58)
Boiled potato (Sebago 87, Desiree 101)	Baked sweet potato (46)
White bagel (72)	Salmon sushi (48)

Article by Pamela Wilson, May 2006.

I got the following information from http://www.weightlossresources.co.uk/diet/gi_diet/sample_plan.htm

GI Diet Plan Sample Day Typical Day's Diet on the GI Plan Breakfast Bowl of porridge made from traditional oats and skimmed milk and sweetened with a little honey. Plus a pear. Mid morning 1 pot low-fat fruit yoghurt and a banana. Lunch Bowl of lentil soup plus an open tuna sandwich made with 2 slices of wholegrain bread, a thin scrape of low-fat spread and tuna in brine. Plus a handful of cherries. Mid afternoon Small pack of low-fat crisps Dinner Spaghetti bolognese (made from extra lean minced beef and lots of vegetables) served with wholewheat spaghetti and salad.

Andrea I hope this answers your questions and if you have others please feel free to leave me a comment with them. All the best with your journey and blog.

Carlton
I am the most important person in the world.