Fasting ghrelin does not predict food intake after short-term energy restriction.
OBJECTIVE
To study the role of ghrelin as a hunger signal during energy restriction and to test the hypothesis that changes in fasting leptin concentrations during energy restriction are associated with changes in fasting ghrelin concentrations.


METHODS
Thirty-five healthy, lean men (23 +/- 3 years of age; BMI: 22.3 +/- 1.6 kg/m(2)) participated in a controlled intervention study. Fasting ghrelin and leptin concentrations were measured before and after 2 days of 62% energy restriction and after a 2-day period of ad libitum food intake. Energy intake during the latter period was assessed.


RESULTS
On average, ghrelin concentrations did not change (0.05 mug/liter; 95% confidence interval, -0.03; 0.12) during energy restriction. Changes in ghrelin concentration during energy restriction were not associated with energy intake during the ad libitum period (r = 0.07; not significant). Ad libitum energy intake was, however, associated with the change in ghrelin concentrations during the same period (r = -0.34; p = 0.05). Ghrelin and leptin concentrations were not associated. In addition, the ratio of percentage changes in ghrelin and leptin during energy restriction was not correlated with ad libitum food intake after energy restriction (r = -0.26; p = 0.14).


CONCLUSIONS
Fasting ghrelin concentrations did not rise after a 2-day energy restriction regimen. Moreover, changes in ghrelin concentrations during energy restriction were not associated with subsequent ad libitum food intake, suggesting that fasting ghrelin does not act as a hunger signal to the brain. The data did not support our hypothesis that leptin suppresses ghrelin levels.
Blom
Wendy A M
WA
TNO Quality of Life, Business Centre Nutrition, Zeist, The Netherlands.
Mars
Monica
M
Hendriks
Henk F J
HF
de Groot
Lisette C P G M
LC
Stafleu
Annette
A
Kok
Frans J
FJ
de Graaf
Cees
C
D000293:Adolescent; D000328:Adult; D031204:Caloric Restriction; D004435:Eating / Q000502:physiology*; D002149:Energy Intake / Q000502:physiology*; D005215:Fasting / Q000097:blood; D005247:Feeding Behavior; D054439:Ghrelin; D006801:Humans; D008297:Male; D008875:Middle Aged; D036361:Peptide Hormones / Q000097:blood*; D011237:Predictive Value of Tests; D013997:Time Factors
D054439:Ghrelin; D036361:Peptide Hormones