Metabolic and hormonal effects of five common African diets eaten as mixed meals: the Cameroon Study.
OBJECTIVE
To evaluate glycaemic and insulinaemic index and in vitro digestibility of the five most common Cameroonian mixed meals consisting of rice+tomato soup (diet A), bean stew+plantains (B), foofoo corn+ndolé (C), yams+groundnut soup (D), and koki beans+cassava (E).


METHODS
Ten healthy non-obese volunteers, aged 19-31 y, with no family history of diabetes or hypertension.


METHODS
A 75 g oral glucose tolerance test followed by the eating of the test diets with carbohydrate content standardized to 75 g every 4 days with blood samples taken at 0, 15, 30, 60, 120 and 180 min. In vitro digestion of each diet according to Brand's protocol.


METHODS
Plasma glucose, cholesterol, triglyceride, insulin and C-peptide, with calculation of glycaemic and insulinaemic index defined as the area under the glucose and insulin response curve after consumption of a test food divided by the area under the curve after consumption of a control food containing the same amount of carbohydrate, and digestibility index.


RESULTS
Glycaemic index (GI) varied from 34.1 (diet C) to 52.0% (diet E) with no statistical difference between the diets, and insulinaemic index varied significantly from 40.2% (C) to 70.9% (A) (P=0.03). The digestibility index varied from 18.9 (C) to 60.8% (A) (P<0.0001), and did not correlate with glycaemic or insulinaemic indices. However, carbohydrate content correlated with GI (r=0.83; P=0.04), digestibility index (r=-0.70; P<0.01), and insulinaemic index (r=0.91; P<0.01). Plasma C-peptide and plasma lipids showed little difference over 180 min following the ingestion of each meal.


CONCLUSIONS
Glycaemic index of these African mixed meals are relatively low and might not be predicted by in vitro digestibility index.
Mbanya
J-C N
JC
Department of Internal Medicine, Faculty of Medicine and Biomedical Sciences, University of Yaoundé 1, Cameroon. jean-claude.mbanya@camnet.cm
Mfopou
J K
JK
Sobngwi
E
E
Mbanya
D N S
DN
Ngogang
J Y
JY
D000328:Adult; D010367:Arachis; D001786:Blood Glucose / Q000032:analysis*; D002096:C-Peptide / Q000097:blood; D002163:Cameroon; D002784:Cholesterol / Q000097:blood; D004032:Diet; D004040:Dietary Carbohydrates / Q000008:administration & dosage; D004063:Digestion; D027742:Dioscorea; D005260:Female; D005951:Glucose Tolerance Test; D038321:Glycemic Index; D006801:Humans; D007328:Insulin / Q000097:blood*; D007700:Kinetics; D018551:Solanum lycopersicum; D008297:Male; D002365:Manihot; D012275:Oryza; D027805:Phaseolus; D014280:Triglycerides / Q000097:blood; D014675:Vegetables; D003313:Zea mays
D001786:Blood Glucose; D002096:C-Peptide; D004040:Dietary Carbohydrates; D007328:Insulin; D014280:Triglycerides; D002784:Cholesterol