Losing the fad? GI Diet special report

Feature

It's the biggest diet breakthrough since, well, the Atkins Diet. The Clintons swear by it. Most of the large supermarket chains are labelling our food by it. But does it really work?

In the eighties, Dr David Jenkins, professor of nutrition at the University of Toronto, was looking at how certain foods affected blood sugar levels in diabetics. He discovered that some altered blood sugar levels dramatically, while others had little effect. From this he developed a scale called the Glycaemic Index, which quite simply ranked foods based on the effect they had on blood sugar levels. He discovered not only were diabetics maintaining stable blood sugar levels, they were also losing weight.

Doctor Jennie Brand-Miller, Professor of Human Nutrition at the University of Sydney and author of many GI books, was one of the first nutritionists to popularise the GI Diet. GI Jennie, as she is often referred to, explains how it works:

Doctor Jennie Brand-Miller

“Maintaining a low GI is effective for controlling the appetite which is the key to weight loss. By avoiding wide fluctuations in blood glucose which appears to stimulate appetite and create insulin, people will feel full up for longer and eat less.”

In lay-dieters terms this means: If you eat healthy slow digesting foods such as brown rice, and resist refined processed foods like pizza, chances are you will lose weight. Healthy foods generally have a low GI, (an apple scores 38) while foods with a high GI will charge you up with insulin and hinder your weight loss chances.

Are your weigh-in scales not bleeping frantically? Isn’t this just common sense?

Nothing new

According to Dr Frankie Phillips, a registered dietician with the British Dietetic Association, this is the message they have been trying to put across for years: “The GI Diet is nothing new and is basically a healthy eating plan. But in terms of weight loss there is still no hard evidence that the GI Diet alone can reduce weight.”

Yet dieticians are fundamentally in agreement that there are health benefits to be gained from following a low GI diet. A study of 90,000 women, published late last year in the American Journal of Clinical Nutrition, showed that women consuming a high GI diet had a 60% greater risk of developing type 2 diabetes than those who ate a lower GI diet.

So why has it taken nearly 25 years for a scientifically proven diet to hit the headlines in the UK when we happily guzzled up gallons of cabbage soup and gobbled tons of fatty Atkins Diet foods without a second thought?

Dr Brand-Miller believes it is because the GI Diet is based on science and is not ‘owned’ by anyone whereas other diets have been driven by marketing: “The GI Diet has hundreds of papers in medical literature behind it. Atkins did not have much at all until very recently and the Cabbage Soup Diet has nothing.”

Gap in market

It wasn’t long before someone noticed the gap in the popular diet market. Rick Gallop, author of the GI Diet and former president of the Heart and Stroke Foundation of Ontario, Canada, repackaged the GI to make it more accessible: “It was complicated for people to work out and not all low GI foods are suitable for weight loss. Haagen Dazs ice-cream is relatively low in GI but you would not eat it as part of a weight loss plan because it’s high in fat. I came up with a simple idea that would be workable for everyone and introduced a traffic light colour code to alert people which foods to avoid.”

He was later approached by Hamish Renton, former head of health and diet for the supermarket chain Tesco, who suggested they team up to promote the diet in the UK.

Today the supermarket GI labels 250 of its key products and has sold over 65,000 copies of the Tesco's GI Guide, a joint venture between Renton and Gallop. Since eight pence in every British pound is spent in Tesco, and since the supermarket has run an intense advertising campaign, it has hit the headlines with phenomenal impact.

Tesco's GI Guide

And they’re not the only ones. Other supermarkets are devising GI labelling systems of their own. Amy Cashmore, a spokesperson for Sainsbury’s said: “Research shows that people who eat a low GI diet are at less risk of developing a number of chronic diseases. The GI logo will appear on products that offer only green and amber segments on the wheel of health, so customers can clearly identify healthy products with a lower GI."

But critics believe that this intense focus on what we eat could have a negative impact on our eating behaviour, regardless of whether a diet is nutritionally sound or not.

Steve Bloomfield, communications manager for the Eating Disorders Association said: “There is no doubt that any form of dieting is likely to become problematic unless it is structured and monitored by a medical professional and there is a real medical need for that person to be on a diet. All these diets do is create an unhealthy obsession with food that can lead to serious health and psychological problems.”

But GI supporters remain convinced that it is an important step towards improving our health. Gallop said: “The fact remains we have an obesity problem because food has become a cheap commodity and it’s very easy to eat big portions. We don’t have to hunt anymore and the industrial production of food has made it increasingly processed. Many people have been yoyo dieting all their lives and have never been taught about basic nutrition. It simply helps consumers make informed choices about what to eat.”

Vicky Matthews, who tested the GI diet for Fad Diets Insight, agrees: “I didn’t realise a lot of the foods I take for granted are bad for me and it’s taught me to think before I eat.”

Whether the GI Diet is just another fad that leaves our lives as quickly as this season’s wardrobe remains to be seen. But Dr Brand-Miller is certain that it will remain popular: “The GI Diet fires people's imaginations, it presses the right buttons. People warm to a message about controlling blood sugar highs and lows. Perhaps they sense how their mood or physical energy levels are affected.”

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