Around conception, during fetal life and in infancy and childhood, nutritional and other environmental variations impact normal development with lasting effects on later health and chronic disease risk. At a time when the collective of noncommunicable diseases (NCDs) is increasingly seen as a public health emergency ‘in slow motion’, the importance of the early life period in healthy development cannot be overstated. Rapid environmental changes are clearly having a detrimental impact, and have seen a sharp rise in allergy and childhood obesity. Nutritional changes are strongly implicated in these and other inflammatory diseases. Although NCDs are seen as diseases of affluence and economic development,the burden is greatest in underprivileged populations. Acute early effects and the resulting maladaptive physiological responses that drive latent long-term effects are responsible for a vicious cycle of epigenetic programming, which has seen childhood obesity driven by maternal obesity.