The low glycaemic index diet Ludwig: Lancet 2007, vol 369, March 17, 890-892
David Ludwig has written a thought provoking article on the glycaemic index(GI) This concept has been around for more than 20 years. The argument for this measure is that it is a guide allowing the classification of health providing properties of carbohydrate meals. Eating simple sugars which are rapidly absorbed is a challenge to the body hormonal system.
GI is determined by measuring the 2 hour incremental area under the glucose curve after taking 50 g of carbohydrate and comparing this with a white bread or glucose load. The higher the GI the greater the potential hormonal challenge to glucose homeostasis. . Glycaemic load (CL) is the average GI multiplied by the carbohydrate amount.
It is also claimed that in times gone past that we ate a diet that was characterised by a lowGI. It is a absolute necessity for any theory that the central element is unchallengeable by measurement. Who knows how our primeval ancestors ate. Feast and famine, hunting ,gathering , good weather ,bad weather, fierce carnivores hunting for the same food .No shop until you drop but hunt and gather before you drop. Early death from all manner of pestilences.
The bolus of food can be seen as a sponge. The glycaemic curve will be dependent upon
time of chewing .
length of time spent ingesting the food or drink e.g. sipping. A simple experiment is sipping a glass of wine or gulping it down.
Eating communally is important. In contrast to the snatched meal.
gastric emptying time. This is determined by the chemistry of the food ingested e.g. fat has the greatest retarding effect. So a piece of white bread coated with butter and a protein paste will have a lower GI than white bread on its own
How the ingested food was prepared .
Each of us has two experiments going. One’s own eating habits and that of people we are advising. What do we really enjoy?
Perhaps GI should only be part of a dietary regime. That the forbidden treats be eaten slowly and in discrete amounts. Food is a real treat in life. There is such a contrast between the snatched sandwich and a couple of pints in a Pub before an important game and the slow meal eaten amongst family and friends for Sunday lunch. Both are fun and should live together. A mix is all important.
- Martin Eastwood