Evidence from both human and animal studies has shown that the prenatal and early postnatal environments influence susceptibility to chronic disease in later life and suggests that epigenetic processes are an important mechanism by which the environment alters long-term disease risk. Epigenetic processes, including DNA methylation, histone modification and non-coding RNAs, play a central role in regulating gene expression. The epigenome is highly sensitive to environmental factors in early life, such as nutrition, stress, endocrine disruption and pollution, and changes in the epigenome can induce long-term changes in gene expression and phenotype. In this review we focus on how the early life nutritional environment can alter the epigenome leading to an altered susceptibility to disease in later life.