This thesis deals with the importance of epigenetics in the accruement of certain diseases like cancer, obesity and diabetes. Several environmental factors, such as nutrition, psychological stress and toxins could lead to epigenetic modifications like altered DNA methylation patterns or histone modifications (histone methylation, histone acetylation, histone phosphorylation). In animal models correlations between these modifications and the development of multiple types of cancer and obesity have already been shown. Although epigenetic changes are reversible, some may be inherited by the offspring. Due to this phenomenon, a healthy lifestyle of the parents could positively influence the prevalence of obesity and metabolic disease.