Good carbohydrate

The Glucose Revolution: Authoritative Guide to the Glycemic Index, The Groundbreaking Medical Discovery by Brand-Miller, Wolever, Colagiuri and Foster-Powell claims to give diabetics literally a new lease on life.

The key is that all carbohydrates are distinct in the way they are digested in the body. As the ode to the Glycemic Index says, "At last research has laid to rest the myth that sugar's not the best".

The Glycemic Index (GI) is a numerical system of ranking foods from 0 to 100, measuring whether a carbohydrate triggers a rise in blood sugar levels "dramatically, moderately or just a little".

The GI, developed in 1981 by Dr David Jenkins, a nutrition professor at aToronto university, still remains relatively unknown. Subsequent research has found that a diet of low GI foods may foster better control of blood glucose levels, and may also allow the body to use insulin more effectively, help the colon function better, and let people with diabetes exercise longer.

Foods with low GI

The World Health Organisation has recommended foods with a low GI be recommended for all diets, regardless of disease status. Although therapists in the U.S. have tended to downplay the value of GI in treating diabetes, practitioners in Canada, Australia New Zealand, France and the UK have used it with good results.

In the control of diabetes, the emphasis has been on the quantity of the carbohydrate in the diet. The authors believe both the amount and type of carbohydrate must be considered in the dietary management of diabetes and using food with lower GI indexes will allow patients to eat more carbohydrates without increasing blood sugar levels.

Digestion and absorption of starchy food is not slower than sugary food, as previously believed, asserts the book and elaborates on various ways to include the right sort of carbohydrates in diets for different lifestyles.

Simply changing from cornflakes at breakfast to rolled oats, lowered the blood sugar level of one patient dramatically and the book suggests many such alternatives.

It also clarifies a lot of misconceptions about simple and complex carbohydrates: One cup of cooked Basmati rice has a lower GI value (58) than a teaspoonful of sugar (65); Sucrose produces a much lower glucose response than the more complex carbohydrate of a baked potato with a value of 93; Chana dal, a part of sub-continent's staple diet, has the lowest GI value of 8.

The application of GI values can be useful for various aspects of health – from control of diabetes and heart problems to weight loss and athletic performance. The book lists the GI values of many common foods and dishes out recipes using low GI value foods for a healthier diet.

But even with all this evidence, the GI should be used as an additional weapon in the arsenal. Total carbohydrate, fat, protein content, and micronutrient levels as well as other factors must all be used in selecting appropriate dietary components. The GI of a food is only one of several measures of its nutritional and metabolic value and should never be used in isolation.

The time factor

Meals eaten earlier in the day result in a more moderate glucose response than that induced by the same meal ingested later. The effect of a low GI meal may also extend to subsequent meals. In one study, a low GI breakfast improved glucose tolerance at the second meal (lunch), and evening meals of a low GI value result in a lower glucose response to a subsequent breakfast.