Mast cells are granulated immune cells with a known role in allergies due to the mediators they release upon activation, for example histamine, leukotrienes, prostaglandins, TNF-α, IL-6, and MCP-1 . Environmental factors like nutrient availability can impact the survival, proliferation and activation of these cells. In this study, we investigated whether fasting induced by reducing the amount of nutrient source, FBS (fetal bovine serum) affects the allergic activation of mast cells. To accomplish this, mature bone marrow-derived mast cells were incubated in media containing different concentrations of FBS overnight along with anti-DNP IgE. The cells were stimulated with DNP-BSA (the antigen) and the activation of cells was quantified using ELISA (for TNF-α and IL-6). Results showed that fasting state prevented TNF-α and IL-6 production in a dose dependent manner, suggesting that fasting state prevents allergic activation of mast cells. Therefore, it can be concluded that a nutrient factor present in the FBS serum contributes to mast cell activation upon allergen challenge. The understanding of the precise mechanisms underlying prevention of mast cell activation to allergens will highlight new therapeutic avenues for hypersensitivities.