Beneficial effects of soy peptide fractions on lipid profiles and appetite‐related hormones in obese rats induced by high fat diet

Abstract

This study aimed at investigating whether dietary peptides had beneficial effects on lowering obesity and body fat as compared with intact protein. Sprague Dawley male rats were divided into four groups (n=8/group) and fed experimental diets containing 18% fat diet with different nitrogen sources and levels, respectively; 10 % soy protein isolate (10SPI), 25% soy protein isolate (25SPI), 25% soy protein hydrolysates (25SPH) and 25% soy macropeptide fractions (25SPP, MW≥10000) for six weeks. Weight gain was significantly higher in 25% nitrogen sources‐fed groups than in 10% group (10SPI). In 25SPP, perirenal fat mass and serum total lipid significantly lower than in other groups. As for appetite‐related hormones, ghrelin was not shown to be different among groups but leptin significantly decreased in 25SPP. It can be concluded that soy peptide fractions as compared with intact soy protein may have beneficial effects on reducing fat mass and serum lipid as well as appetite regulation.