Poor analytical techniques are used in determining Glycemic Index. The basic assumption that a "50-g carbohydrate portion of a food" , i.e. a portion of food containing 50 g of digestible carbohydrate, can be compared with 50g of glucose is erroneous. As both of these food portions have differing chemical units, the calculation of GI by comparing "areas under curves" does not give a dimensionless GI number. The resultant "GI number" has units "g glucose released from a portion of food containing 50 g of digestible carbohydrate per g glucose". Only food containing pure glucose and/or starch can have a true Glycemic Index. Other carbohydrate foods such as the simple sugars fructose and galactose and the di-saccharides lactose and sucrose need considerable processing by the body before they become glycemic. For example, fructose is partially converted to glucose by the liver. However, the amount converted is dependent on both blood glucose and liver glycogen storage levels. As any excess fructose cannot be stored in the liver, it is converted to fatty acids for subsequent storage as body fat. In this case. not all fructose is converted to blood glucose within the prescribed reference time of say 2 hours.This means that the total grams of digestible fructose overestimates the amount of fructose converted to blood glucose over the reference time. This results in giving false low Glycemic Index values for fructose.
The following passage in the article represents original (and massively incorrect) research and needs to be removed -
"In spite of the common belief that table sugar contributes to the development of diabetes, it has medium (55–69) GI that produces lower blood glucose levels than the equal amount of calories obtained from starch and some other carbohydrates."
This passage attempts to make an original claim about diabetes pathology based on a factually-incorrect ignorance of the specific consequences of fructose consumption on liver insulin sensitivity. 22.214.171.124 (talk) 08:29, 2 August 2012 (UTC)
I have no idea what this means, glycemic index is metric for foods, and body weight is a metric for people. Perhaps the writer is implying that you can still get fat eating low glycemic foods, but that is obvious: "Some research has shown that glycemic index and glycemic load are not associated with body weight status." --Richard Arthur Norton (1958- ) (talk) 23:30, 20 June 2014 (UTC)