a1 Department of Nutrition and Food Hygiene, School of Public Health, Harbin Medical University, Harbin, Heilongjiang, People's Republic of China
Gut hormones play key roles in the regulation of energy homeostasis. However, little is known about the long- and short-term effects of changing dietary fat content on gut hormones. We aim to examine the effects of changing dietary fat content on plasma gut hormone concentrations in diet-induced obese (DIO) and diet-resistant (DR) rats. After inducing obesity with a high-fat (HF) diet, male Sprague–Dawley rats were divided into three groups according to their body-weight gain: DIO; DR; control (CON). The DIO and DR rats were further divided in random into two groups. One continued on a HF diet and the other switched to a low-fat (LF) diet for an additional 4 weeks. Finally, each group was randomly divided into three subgroups (n 8): fasted; fasted-refed HF; fasted-refed LF diet groups. Replacing a HF diet with a LF diet for 4 weeks resulted in less fat mass, higher fasting and post-HF plasma ghrelin concentration and lower postprandial plasma cholecystokinin concentration in the DIO and DR rats. Acute switching dietary fat resulted in significantly higher post-HF plasma ghrelin concentrations than post-LF ghrelin concentrations in the DR rats on LF diet (DRLF) and DIO rats on LF diet (DIOLF) rats, and significantly higher post-HF obestatin concentrations than post-LF obestatin concentrations in the CON, DR rats on HF diet (DRHF) and DRLF rats. Dietary fat content appears to play a role in the gut hormone profile, which may consequently influence fat mass.
(Received January 25 2010)
(Revised September 04 2010)
(Accepted September 28 2010)
(Online publication November 09 2010)
Abbreviations: CCK, cholecystokinin; CON, control; DIO, diet-induced obesity; DIOHF, diet-induced obese rats on a high-fat diet; DIOLF, diet-induced obese rats on a low-fat diet; DR, diet resistant; DRHF, diet-resistant rats on a high-fat diet; DRLF, diet-resistant rats on a low-fat diet; GLP-1, glucagon-like peptide 1; HF, high fat; LF, low fat; PYY, peptide tyrosine–tyrosine; WAT, white adipose tissue