GI Update

Professor Jennie Brand-Miller answers your questions

Does the carbohydrate content on a food’s nutrition label have any relationship to its blood glucose-raising capacity?
Yes, but only to some extent. We can make a few generalisations. If a food has less than 5 grams of carbohydrate per serving, then it won’t have a marked effect on your blood glucose levels. If it has 10 or more grams it’s likely to have a substantial effect, depending on the food’s GI value. So all the label can tell you is whether the food is high or low in carbohydrate. If the food is high in carbohydrate, then its GI is much more relevant. A food that’s both high in carbohydrate and has a high GI could be contributing to high blood glucose readings.

Studies tell us that diets based on frequent consumption of high GI value carbohydrates will put us at greater risk of developing type 2 diabetes, heart disease and some forms of cancer. It’s not the amount of carbohydrate that matters, it’s the source. High carbohydrate diets from high GI sources spell trouble, especially for people with insulin resistance, which is one of the underlying causes of type 2 diabetes. That’s why we believe that any changes to front-of-pack food labelling schemes must move beyond the current focus on added sugars and include the glycemic impact of the food’s carbohydrates if our government health departments are really concerned about reducing the risk of type 2 diabetes.

In our most recent paper published in the American Journal of Clinical Nutrition, we showed that the glycemic load of food may be more effective than the available carbohydrate content in calibrating how much insulin patients with type 1 diabetes should take before meals. In two studies, glycemic load repeatedly outperformed carb content in predicting the increase in blood glucose and insulin levels up to two hours after eating in 10 healthy young people who consumed 121 types of single foods (study 1) and 13 mixed meals (study 2).

GI testing by an accredited laboratory
North America
Dr Alexandra Jenkins
Glycemic Index Laboratories
20 Victoria Street, Suite 300
Toronto, Ontario M5C 298 Canada
Phone +1 416 861 0506
Email info@gilabs.com
Web www.gilabs.com

Australia
Fiona Atkinson



Research Manager, Sydney University Glycemic Index Research Service (SUGiRS)
Human Nutrition Unit, School of Molecular and Microbial Biosciences
Sydney University
NSW 2006 Australia
Phone + 61 2 9351 6018
Fax: + 61 2 9351 6022
Email sugirs@mmb.usyd.edu.au
Web www.glycemicindex.com

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Compounds found in tea, called theaflavins and thearubigins, prevent obesity

But don't drink your tea with milk! A study by scientists in Japan, which is published this month in the journal of Nutrition, reveals that extracts from tea leaves inhibits the absorption of fat in the gut of rats being fed high fat diets. These rats also had less fat tissue on their bodies and lower fat content in their livers. The researchers now believe this could explain why people in Britain appear not to benefit from the healthy affects of tea despite being among the world's biggest consumers of the beverage. Dr. Devajit Borthakur, a scientist the Tea Research Association, in Jorhat, India, said: "When tea is taken with milk, theaflavins and thearubigins form complexes with the milk protein, which causes them to precipitate. "It means that we don't get the health benefit from these compounds nor from milk protein. Therefore, it is always advised to take tea without milk.

Gastric banding caused more complications than weight loss

About 220,000 people underwent weight-loss surgery in 2009, up since 2000 when 36,700 operations were performed, according to the American Society for Metabolic and Bariatric Surgery in Gainesville, Florida. Gastric banding represents about one-third of that total. Almost half of patients undergoing gastric banding for obesity needed to have the device removed, often because of erosion, according to a study that found the treatment caused more complications than weight loss. “I personally no longer perform band gastroplasty, but I think it is defendable for surgeons to continue doing this,” said Jacques Himpens, the study’s lead author who works with the European School of Laparoscopic Surgery at Saint Pierre University Hospital in Brussels. “Patients should not expect too much from the procedure. If they do get the operation, they must commit themselves to lifelong and very tight follow-up.”

US breakfast are often unhealthy for children

According to a statement from the Institute of Food Technologists in the US breakfasts served to children worldwide are often high in sugar and saturated fat and low in dietary fibre. These lack essential vitamins and minerals. It impacts public health and has consequences for personal health. It cites several studies that illustrate the importance of breakfast in improving cognitive function and weight management for children, factors that are critical to curb obesity among children and adolescents. What makes a good breakfast for children? One good example would be an egg, a slice of whole grain toast with nut butter, a piece of fruit and a glass of low-fat milk. Tofu, lean meat and whole grain cereals are also good choices at breakfast. The protein and fiber from the whole grains will keep your child satisfied until lunch time.

BIB balloon can lead to significant weight loss

The so-called BIB balloon system partially fills the tummy, so the patient feels full after eating only small amounts of food. The silicone balloon is inserted into the stomach through the mouth with the help of a gastroscope — a thin hollow tube which is used to feed in surgical instruments. Once in place, the expandable balloon is filled with 500ml of a blue-coloured solution, through a tube in the gastroscope. This acts to reduce the capacity of the stomach by a quarter — the stomach’s maximum capacity normally is two litres. The coloured solution allows a patients to quickly detect any leakage as the liquid will turn their urine blue. The balloon is designed to be kept in place for six months. The balloon can lead to a reduction of 10 percent of body weight over a year, whereas a gastric band, as used by Fern Britton, can help lose up to 30 per cent.

After this, the surgeon uses a gastroscope to remove it if the patient has lost a sufficient amount of weight, or replace it with another balloon. Although the technology has been available for some years, evidence now shows it can be a safe alternative to weight-loss surgery, and more doctors are now turning to the procedure for moderately obese patients. Source: MailOnline

The Three-hour Diet

This diet is simple: eat every three hours and you’ll lose weight. The diet demands that users eat breakfast, lunch, dinner and snacks in between. The author of the three-hour diet claims it can lower your body fat and burn two pounds a week without any exercise. The main meals are very specific and call for fruits and vegetables the size of DVD cases, a deck of cards sized protein, a Rubik’s cube of carbs and fat that fits in a bottle cap. However, the snacks can be anything, even candy, as long as it amounts to around 100 calories. Critics of the diet said eating more often could cause an overload on calories if you have a tendency to overeat at meals.

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