Coating beef tallow with calcium soap improves dietary pellet quality and promotes an effective diet-induced obese mouse model

•High-fat diets with natural ingredients are used, because of the difficulty in accessing high-fat purified diets in some countries.•High-fat diets with natural ingredients begin to oxidize quickly at room temperature and they are low pellet resistance and easy deformation.•Therefore, reducing this deterioration in high-fat diets with natural ingredients may be possible by using a coated technological oil sources.•Ca-HFD having high pellet quality (durability) and low peroxide values had better qualities than the HFD.•HFD or a Ca-HFD can be used in modeling obesity in mice, but only an HFD is a recommended candidate for modeling type 2 diabetes. The obesity model is predominantly formed by feeding animals that are prone to obesity with high-fat diets, but this dietary intervention is not standardized. It is very difficult to pellet most high-fat diets, as they become rapidly oxidized due to their high-fat content. This study aimed to use calcium soap (Ca-soap) of beef tallow as a source of fat in high-fat mouse diets and to investigate its effects on pellet quality and its effectiveness in an obesity model. In the experiment, three diets were formed: a control diet (CD), a high-fat diet with beef tallow (HFD), and a high-fat diet containing beef tallow and Ca-soap of beef tallow (Ca-HFD). A total of 36 male C57BL/6 J mice aged six weeks were randomly divided into 3 groups: the Control (C), High-Fat (HF), and High-Fat with Ca-soap (Ca-HF) groups. The experiment lasted 20 weeks. Ca-HFD and HFD had higher hardness and pellet durability index (PDI) values than CD. Ca-HFD had a lower peroxide value than that of the HFD. At the end of the study, average body weight, body weight gain, food consumption, and calorie consumption were found to be the highest in the HF group and the lowest in the C group. The highest epididymal white adipose tissue (eWAT) ratio of the mice was seen in the Ca-HF group. Plasma triglyceride and insulin values ​​were higher in the HF group than in the C group. The highest level of steatosis was observed in the HF group. High body weight gain, fat deposition, hypercholesterolemia, hyperglycemia, glucose tolerance, and hepatic steatosis were observed in C57BL/6 J male mice fed the high-fat diets, but only HFD caused hyperinsulinemia. HFD and Ca-HFD can be used to model obesity, but only HFD can be used in type 2 diabetes modeling.