Background: food additives are substances used in food industry in order to improve the food's taste, appearance by preserving its flavor and preventing it from souring. Food additives are added to the most junk and fast foods, especially food for kids. Aim of the work: this work was aimed to investigate the adverse effects of some food additives on the biochemical parameters in addition to study the side effects of these food additives in male albino rats. Materials and Methods: this study was performed on twenty four young male albino rats with an average 120-145 g body weight. Animals were divided into four groups (6 /cage); Group I (Control untreated group), Group II (administered orally with sodium nitrite (0.1 mg/kg b.wt./day) and annatto (0.065 mg/kg b.wt./day)), Group III (administered orally with sodium nitrite (0.1 mg/kg b.wt./day) and monosodium glutamate (MSG) (15 mg/kg b.wt./day)) and Group IV (administered orally with annatto (0.065 mg/kg b.wt./day) and monosodium glutamate (15 mg/kg b.wt./day)). Blood samples were collected on the last day of experiment, for biochemical estimations which included levels of serum glucose, total protein (TP), albumin, creatinine, urea, testosterone , thyroid hormones (T3 and T4), activities of AST and ALT in addition to lipid profile. Results: showed marked elevation in levels of fasting glucose, activities of AST, ALT, urea, creatinine, total cholesterol (TC), triglycerides (TG) and high density lipoprotein cholesterol (HDL-C), VLDL and ratios of TC/HDL-C and LDL-C/HDL-C (risk factors) as well as albumin / globulin ratio and serum thyroid hormones (T3 & T4) accompanied with marked decline in levels of serum total proteins, albumin, globulin, albumin/ creatinine ratio, testosterone and HDL-C in all treated groups in comparison to the control group. There was a significant reduction in the body weight in groups that received (NaNO2 with annatto) and (MSG with NaNO2) while treated rats with (MSG and annatto) showed a significant increase in body weight as compared to control rats. Conclusion: Due to the harmful effects of food additives, the use of these compounds must be limited as it resulted in a vehement disturbance in the biochemical and physiological parameters that was grievously pronounced on many hormones.