Overeating of palatable food is associated with blunted leptin and ghrelin responses.
Author
Summary, in English
Palatable food is rich in fat and/or sucrose. In this study we examined the long-term effects of such diets on food intake, body weight, adiposity and circulating levels of the satiety peptide leptin and the hunger peptide ghrelin. The experiments involved rats and mice and lasted 5 weeks. In rats, we examined the effect of diets rich in fat and/or sucrose and in mice the effect of a high fat diet with or without sucrose in the drinking water. Animals fed with the palatable diets had a larger intake of calories, gained more weight and became more adipose than animals fed standard rat chow. Fasted animals are known to have low serum leptin and high serum ghrelin and to display elevated serum leptin and lowered serum ghrelin postprandially. With time, a sucrose-rich diet was found to raise the fasting level of leptin and to lower the fasting level of ghrelin in rats. A fat-rich diet suppressed serum ghrelin without affecting serum leptin; high sucrose and high fat in combination greatly reduced serum ghrelin and raised serum leptin in the fasted state. The mRNA expression of leptin in the rat stomach was up-regulated by sucrose-rich (but not by fat-rich) diets, whereas the expression of ghrelin seemed not to be affected by the palatable diets. Mice responded to sucrose in the drinking water with elevated serum leptin (fasted state) and to all palatable diets with low serum ghrelin. The expression of both leptin and ghrelin mRNA in the stomach was suppressed in fasted mice that had received a high fat diet for 5 weeks. We conclude that the expression of leptin mRNA in stomach and the concentration of leptin in serum were elevated in response to sucrose-rich rather than fat-rich diets, linking leptin with sucrose metabolism. In contrast, the expression of ghrelin and the serum ghrelin concentration were suppressed by all palatable diets, sucrose and fat alike. In view of the increased body weight and adiposity neither elevated leptin nor suppressed ghrelin were able to control/restrain the overeating that is associated with palatable diets.
Department/s
- Appetite Regulation
- Neuroendocrine Cell Biology
- Department of Experimental Medical Science
- Drug Target Discovery
Publishing year
2005
Language
English
Pages
123-132
Publication/Series
Regulatory Peptides
Volume
130
Issue
Jun 16
Links
Document type
Journal article
Publisher
Elsevier
Topic
- Cell and Molecular Biology
Keywords
- fasting
- sucrose
- leptin
- ghrelin
Status
Published
Research group
- Appetite Regulation
- Neuroendocrine Cell Biology
- Drug Target Discovery
ISBN/ISSN/Other
- ISSN: 1873-1686