OBJECTIVETo investigate the effects of long-term high-protein, low-carbohydrate diet on body weight and the expression of gastrointestinal hormones in diet-induced obesity rats.

METHODSTwenty-four diet-induced obesity rat models were established by feeding fat-enriched diet, then were randomly divided into two groups by stratified sampling method by weight: the high-protein diet group (HP, 36.7% of energy from protein), and the normal chow group (NC, 22.4% of energy from protein), 12 rats in each group. The total calorie intake of each rat per day was similar and was maintained for 24 weeks, then body weight, visceral fat mass, fasting plasma ghrelin and glucagon-like peptide-1 (GLP-1) were determined, as well as protein expression of ghrelin in stomach, GLP-1 in ileum were detected by immunohistochemistry.

RESULTSAfter 24 weeks, body weight of HP, NC groups were (490.92 ± 39.47) g and (545.55 ± 31.08) g, respectively (t = -3.664, P < 0.01); visceral fat mass were (22.42 ± 7.04) g and (32.33 ± 9.27) g, respectively (t = -2.503, P < 0.05); plasma ghrelin level were (2.36 ± 0.82) and (1.95 ± 0.64) ng/ml, respectively (t = 1.337, P > 0.05), and plasma ghrelin level was negatively correlated to body weight (r = -0.370, t = -1.899, P < 0.05), visceral fat mass (r = -0.454, t = -2.52, P < 0.01); plasma GLP-1 concentration were (0.52 ± 0.13) and (0.71 ± 0.19) ng/ml, respectively(t = -2.758, P < 0.05); ghrelin protein expression in stomach were 25 473 ± 8701 and 10 526 ± 6194, respectively (t = 2.501, P < 0.05); GLP-1 protein expression in ileum were 27 431 ± 5813 and 36 601 ± 5083, respectively (t = -1.833, P = 0.081).

CONCLUSIONLong-term isocaloric high-protein, low-carbohydrate diet can reduce body weight and visceral fat, increase the expression of ghrelin, and decline GLP-1 expression in diet-induced obesity rats.