Glycemic index, cholecystokinin, satiety and disinhibition: is there an unappreciated paradox for overweight women?
BACKGROUND
The clinical utility of a low glycemic index (LGI) diet for appetite and food intake control is controversial. Complicating the issue are psychological and behavioral influences related to eating.


OBJECTIVE
The aim of this study was to investigate the satiety and glycemic response to high GI (HGI) and LGI meals in overweight restrained (R, n=12) and unrestrained (UR, n=10) women.


METHODS
In a randomized crossover study, subjective satiety, cholecystokinin (CCK), glucose, insulin, triacylglyceride (TG) and free fatty acids (FFAs) were measured at defined intervals for 8 h after the participants consumed HGI or LGI test meals. Test meals were matched for energy, energy density, macronutrient content and available carbohydrate, but differed by carbohydrate source; refined grain versus whole grain, respectively.


RESULTS
The HGI meal resulted in greater satiety overall, suppressing hunger, desire to eat and prospective consumption compared with the LGI (P<0.01) meal. Plasma CCK was significantly elevated after the HGI meal compared with the LGI meal (P<0.001). Plasma glucose, insulin and TG were higher and FFAs were lower after the HGI meal compared with the LGI meal (P<0001). Dietary restraint did not significantly influence CCK (P=0.14) or subjective satiety (P>0.4); however, an interaction of restraint and disinhibition on CCK was apparent. CCK was blunted in R participants with higher disinhibition scores than UR or R participants with lower disinhibition scores (P<0.05).


CONCLUSIONS
A LGI diet may not be suitable for optimal satiety and appetite control in overweight women. The relationship between cognitive influences of eating and biobehavioral outcomes requires further investigation.
Burton-Freeman
B M
BM
Department of Nutrition, University of California, Davis, CA, USA. bburton@iit.edu
Keim
N L
NL
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D002766:Cholecystokinin / Q000097:blood*; D018592:Cross-Over Studies; D003463:Cues; D050528:Diet, Carbohydrate-Restricted / Q000523:psychology; D004040:Dietary Carbohydrates / Q000494:pharmacology; D004041:Dietary Fats / Q000494:pharmacology; D004435:Eating / Q000523:psychology; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D038321:Glycemic Index / Q000502:physiology*; D006801:Humans; D007328:Insulin / Q000097:blood; D008875:Middle Aged; D050177:Overweight / Q000378:metabolism* / Q000523:psychology; D012527:Satiation / Q000502:physiology; D014280:Triglycerides / Q000097:blood; D055815:Young Adult
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D005230:Fatty Acids, Nonesterified; D007328:Insulin; D014280:Triglycerides; D002766:Cholecystokinin