Purpose. The purpose of this study was to determine, on the animal model, the effect of modifi cation of diet composition and administration of selected food additives on water balance in the body.

Material and methods. The study was conducted with 48 males and 48 females (separately for each sex) of Wistar strain rats divided into four groups. For drinking, the animals from groups I and III were receiving water, whereas the animals from groups II and IV were administered 5 ml of a solution of selected food additives (potassium nitrate – E 252, sodium nitrite – E 250, benzoic acid – E 210, sorbic acid – E 200, and monosodium glutamate – E 621). Doses of the administered food additives were computed taking into account the average intake by men, expressed per body mass unit. Having drunk the solution, the animals were provided water for drinking.

Results. The mixture of selected food additives applied in the experiment was found to facilitate water retention in the body both in the case of both male and female rats, and differences observed between the volume of ingested fl uids and the volume of excreted urine were statistically signifi cant in the animals fed the basal diet. The type of feed mixture provided to the animals affected the site of water retention – in the case of animals receiving the basal diet analyses demonstrated a signifi cant increase in water content in the liver tissue, whereas in the animals fed the modifi ed diet water was observed to accumulate in the vascular bed.

Conclusion. Taking into account the fact of water retention in the vascular bed, the effects of food additives intake may be more adverse in the case of females.