No difference in body weight decrease between a low-glycemic-index and a high-glycemic-index diet but reduced LDL cholesterol after 10-wk ad libitum intake of the low-glycemic-index diet.
BACKGROUND
The role of glycemic index (GI) in appetite and body-weight regulation is still not clear.


OBJECTIVE
The objective of the study was to investigate the long-term effects of a low-fat, high-carbohydrate diet with either low glycemic index (LGI) or high glycemic index (HGI) on ad libitum energy intake, body weight, and composition, as well as on risk factors for type 2 diabetes and ischemic heart disease in overweight healthy subjects.


METHODS
The study was a 10-wk parallel, randomized, intervention trial with 2 matched groups. The LGI or HGI test foods, given as replacements for the subjects' usual carbohydrate-rich foods, were equal in total energy, energy density, dietary fiber, and macronutrient composition. Subjects were 45 (LGI diet: n = 23; HGI diet: n = 22) healthy overweight [body mass index (in kg/m(2)): 27.6 +/- 0.2] women aged 20-40 y.


RESULTS
Energy intake, mean (+/- SEM) body weight (LGI diet: -1.9 +/- 0.5 kg; HGI diet: -1.3 +/- 0.3 kg), and fat mass (LGI diet: -1.0 +/- 0.4 kg; HGI diet: -0.4 +/- 0.3 kg) decreased over time, but the differences between groups were not significant. No significant differences were observed between groups in fasting serum insulin, homeostasis model assessment for relative insulin resistance, homeostasis model assessment for beta cell function, triacylglycerol, nonesterified fatty acids, or HDL cholesterol. However, a 10% decrease in LDL cholesterol (P < 0.05) and a tendency to a larger decrease in total cholesterol (P = 0.06) were observed with consumption of the LGI diet as compared with the HGI diet.


CONCLUSIONS
This study does not support the contention that low-fat LGI diets are more beneficial than HGI diets with regard to appetite or body-weight regulation as evaluated over 10 wk. However, it confirms previous findings of a beneficial effect of LGI diets on risk factors for ischemic heart disease.
Department of Human Nutrition, Centre for Advanced Food Studies, The Royal Veterinary and Agricultural University, 30 Rolighedsvej, DK-1958 Frederiksberg C, Denmark. bsl@kvl.dk
Birgitte
B
Sloth
Inger
I
Krog-Mikkelsen
Anne
A
Flint
Inge
I
Tetens
Inger
I
Björck
Sophie
S
Vinoy
Helena
H
Elmståhl
Arne
A
Astrup
Vincent
V
Lang
Anne
A
Raben
D000328:Adult; D001786:Blood Glucose / Q000187:drug effects; D015992:Body Mass Index; D001835:Body Weight / Q000187:drug effects*; D008078:Cholesterol, LDL / Q000097:blood*; D003924:Diabetes Mellitus, Type 2 / Q000517:prevention & control; D004040:Dietary Carbohydrates / Q000008:administration & dosage / Q000494:pharmacology*; D004041:Dietary Fats / Q000008:administration & dosage / Q000494:pharmacology*; D002149:Energy Intake; D005260:Female; D038321:Glycemic Index / Q000187:drug effects*; D006801:Humans; D007328:Insulin / Q000097:blood; D009765:Obesity / Q000188:drug therapy / Q000378:metabolism
D001786:Blood Glucose; D008078:Cholesterol, LDL; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D007328:Insulin