Leptin deficiency and leptin resistance induce alterations in cytokine production and increase the susceptibility towards infectious diseases.[8] There are studies that associate the effects of an increased body mass index, which induces leptin resistance, as well as the effects of malnutrition, which induces leptin deficiency, with the likelihood of developing bacterial and viral lung infections, and also parasitic infections.[1,38]. This evidence concerns the gene LEP and nutritional deficiency disease.