Dietary Glycomacropeptide Increases Fat‐Free Mass, Bone Mineral Content and Fatty Acid Oxidation Compared With Casein In Female Mice

Abstract

BackgroundGlycomacropeptide (GMP) is a 64 amino acid (AA) glycophosphopeptide released from κ‐casein during cheese making that promotes satiety, reduces body fat, increases bone mass and infers prebiotic and anti‐inflammatory effects.ObjectiveTo determine if GMP, when fed as the primary protein source, modulates feed efficiency, weight gain and body composition and increases fat oxidation compared with casein.MethodsWeanling female C57Bl6 mice were fed high and low fat diets (HF 60% en; LF 13% en) with casein or GMP for 28 wks with assessment of body weight and food intake. Body composition was assessed by DXA. Fatty acid oxidation was measured in liver, muscle, and fat tissues using 14C‐palmitate. Plasma concentrations of amino acids, hormones and cytokines were determined.ResultsDespite similar food intake, mice fed the HF GMP diet had significantly lower final body weight than mice fed the HF casein diet. Fat free mass was increased in mice fed the LF GMP diet relative to the LF casein diet with similar final body weight but greater food intake. Regardless of dietary fat content, GMP significantly increased bone mineral content (BMC) and fatty acid oxidation in subcutaneous fat compared to casein.ConclusionsGMP reduces feed efficiency, modulates body composition to increase fat free mass and BMC, and increases fat oxidation compared to casein in female mice. GMP is a bioactive food ingredient with application to obesity and osteopenia in females.Support or Funding InformationSupported by the Wisconsin Alumni Research Foundation, NIH T32 DK 007665, and USDA Hatch WIS01790.