In terms of nutrigenomics, and thus taking into account the mechanism of action of lactoferrin on the human body as well as biochemical dysfunctions resulting from genotype, lactoferrin can be proposed as a possible nutraceutical of importance not only in the treatment of overweight and obesity but also in their prevention in people with strong predispositions. The gene discussed is LTF; the disease is obesity due to melanocortin 4 receptor deficiency.