PURPOSE:

This study was conducted to investigate whether a higher proportion of protein or fat is more favorable for optimal ghrelin and peptide YY (PYY) release in subjects consuming low carbohydrate meals.

METHODS:

Eight normal weight men received, on three separate occasions, high protein low fat (HPLF) (40% protein, 25% fat), low protein high fat (LPHF) (10% protein, 55% fat) or medium protein medium fat (MPMF) (25% protein, 40% fat) meals, with equal low carbohydrates content in all three meals (35% of energy). Postprandial blood samples were collected before and 15, 30, 60, 120, 180 and 240 min following the ingestion of each meal. Plasma acylated ghrelin and PYY(3-36) as well as serum insulin, glucose and triglycerides were measured.

RESULTS:

Comparing meals and considering each time point separately, a trend for a statistically significant difference in acylated ghrelin was observed between HPLF and LPHF meals and a statistically significant change of PYY from baseline was noted between HPLF and LPHF meals as compared to the MPMF meal at certain time points. When data were pooled together, a statistically significant difference in acylated ghrelin change from baseline was observed between HPLF and LPHF meals, while both HPLF and LPHF meals resulted in a significantly higher PYY(3-36) release in comparison to MPMF meal. AUC data analysis for PYY(3-36) revealed significantly higher values following HPLF in comparison to MPMF meal. Correlation analysis revealed a significant negative correlation between acylated ghrelin and insulin only with the HPLF meal. Postprandial glucose and triglyceride levels were not significantly different between the three meals.

CONCLUSIONS:

In subjects consuming low carbohydrate meals, higher concentrations of proteins to fat seem to have more favorable effects on postprandial appetite hormones.