Plasma ghrelin response following a period of acute overfeeding in normal weight men.
BACKGROUND
Ghrelin, a 28 amino-acid peptide secreted primarily from the stomach has been identified as the endogenous ligand for the growth hormone secretagogue receptor. Ghrelin is suppressed in the postprandial state and has been linked to both type II diabetes and obesity.


OBJECTIVE
To investigate the effects of a period of overfeeding with high-fat dietary supplements on plasma ghrelin levels in nonobese men.


METHODS
Six healthy males (21-34 y; BMI 21-24 kg/m(2)) underwent the dietary intervention after completing diet and exercise diaries for 7 days. For 3 further weeks subjects followed their own diet diary supplemented with 125 ml single cream and 50 g roasted peanuts (88 g fat, 15 g Protein, 8 g carbohydrate) every day. Oral fat tolerance tests (OFTT) were undertaken at baseline, 7, 14 and 21 days of fat supplementation. The diet was increased in energy by 3.9 MJ/day and from a mean of 29-45% energy intake from fat with a small weight gain noted each week (P=0.009).


RESULTS
Ghrelin concentrations were significantly reduced during the baseline OFTT. The postprandial ghrelin response (AUC) was significantly reduced following 2 weeks of dietary supplementation (P=0.005) increasing the suppression of plasma ghrelin by 18% despite only a 3% increase in body weight. Plasma triacylglycerol (P=0.009) and leptin (P=0.035) concentrations were also elevated and postprandial pancreatic polypeptide levels decreased (P=0.038) following dietary-supplementation.


CONCLUSIONS
These results suggest that the metabolic profile associated with obesity, including a reduction in plasma ghrelin levels, may be related to recent dietary energy intake and precedes the development of significant adiposity.
Robertson
M D
MD
Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford, UK. denise.robertson@oxlip.ox.ac.uk
Henderson
R A
RA
Vist
G E
GE
Rumsey
R D E
RD
D000328:Adult; D000704:Analysis of Variance; D001835:Body Weight / Q000502:physiology*; D004041:Dietary Fats / Q000008:administration & dosage*; D004435:Eating / Q000502:physiology*; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005746:Gastric Emptying / Q000502:physiology; D054439:Ghrelin; D006801:Humans; D020738:Leptin / Q000097:blood; D008297:Male; D036361:Peptide Hormones / Q000097:blood*; D019518:Postprandial Period; D014280:Triglycerides / Q000097:blood; D015430:Weight Gain / Q000502:physiology
D004041:Dietary Fats; D005230:Fatty Acids, Nonesterified; D054439:Ghrelin; D020738:Leptin; D036361:Peptide Hormones; D014280:Triglycerides