The prevalence of obesity has been increased and has become a public health problem globally. Many strategies were done to treat obesity. This study was conducted to modify the ketogenic diet (KD) by replacing the animal fat by vegetable oils to reduce the bad effects of the traditional ketogenic diet. Seventy-two adult male albino rats were divided into two main groups, the first main group (A) (n=6) was fed on the basal diet and kept as negative control group (-ve), the second main obese group (B) rats (n=66) were divided into 11 subgroup 6 rats each. Subgroup (B1) was fed on high fat diet and served as positive control group (+ve). The obese subgroups from (B2-B6) were divided according to the first type of KD at (4:1), to subgroup (B2) was considered a positive control group for the KD at (4:1). While the other 4 subgroups (B3 to B6) were treated by a mixture of different oils including (olive, sesames, flaxseed). The other obese subgroups from (B7-B11) were divided according to the second type of KD at (6:3:1) to, subgroup (B7) was considered a positive control group for the KD at (6:3:1). While the other subgroups (B8 to B11) were treated by a mixture of different oils including the previous oils. At the end of the experiment (6 weeks), blood samples were collected to obtain Serum samples for biochemical assays. The obtained results showed that, after applying the different types of ketogenic diet (4:1) or (6:3:1) using different vegetable oils mixtures of (olive, flaxseed and sesame oils), obese rats had significant weight reduction (P<0.05), as well as improving lipid profile, blood glucose, liver and kidney functions as compared to control positive groups. The study recommends replacing the traditional ketogenic diet with the modified ketogenic diet (depends on mixture of vegetable oils), at the tested ratio in order to benefit from the nutritional value of these plant oils that have useful effect on the body function.