The effect of diets with low vs. high glycemic index on plasma levels of leptin and ghrelin in obese patients
Issue: 4/2014
Author: Handjieva-Darlenska, Teodora S.1, Karamfilova, Vera N.2, Kamenov, Zdravko A.2,
Boyadjieva, Nadka I.1
1 Department of Pharmacology and Toxicology, Medical Faculty, Medical University, Sofia
2 Clinic of Endocrinology, Alexandrovska hospital, Medical Faculty, Medical University, Sofia
Abstract:
The hypothalamus is the main site for regulation of appetite and metabolism. Two major hormones play a role in this regulation – leptin which decreases appetite, and ghrelin which increases appetite. There are not enough data in the literature concerning the effect of different dietary factors (lipids, proteins, glycemic index) on the balance between ghrelin and leptin in obesity.
Therefore, the aim of our study was to examine the effect of two diets varying by glycemic index (low vs. high) on the plasma levels of ghrelin and leptin, and on the anthropometrical parameters in obese subjects.
Materials and methods. A 16-week randomised, controlled, dietary intervention was performed in subjects with overweight and obesity. The total number was 30 (men and women) with a mean age of 46 years (26-62), mean body mass index (BMI) of 32,8 (26-43) кг/m2. Those subjects who met all the inclusion criteria and none of the exclusion criteria were enrolled in the study and randomised in two dietary arms varying by glycemic index (low vs. high). At the begining and at the end of the study the following parameters were measured: body weight, BMI, waist and hip circumferences, waist-to-hip ratio, fat mass (% and kg), fat free mass, arterial pressure, plasma levels of ghrelin and leptin.
Results. The rеsults showed higher reduction in body weight in the group on a low glycemic index (LGI) diet in comparison with the group on a high glycemic index (HGI) diet. The glycemic index of foods didn’t exert any effect on the plasma levels of ghrelin and leptin. However, in the group on a LGI diet a slight decrease in leptin concentrations was detected.
Conclusion. The LGI diet has a beneficial effect on the parameters of obesity. More studies are needed to demonstrate the long-term effect of these diets in the regulation of appetite and metabolism.
Keywords: ghrelin, leptin, obesity, glycemic index
