Reproduction is our biological reason for being. Evolution has shaped us via countless millennia with this one purpose in mind. Our development from an early embryo through to adulthood is geared to making us fit to reproduce, a process that is closely connected to nutrition and energy stores. Seasonal and other fluctuations in food supply has been a key evolutionary shaper of the reproductive process, as illustrated by seasonal breeding species. Humans have echoes of this seasonality and nutrition/energy stores have well-established relationships to puberty timing and fertility, at least in females. In view of the central importance of reproduction and the intimate relationship between nutrition and reproduction, it can be hypothesized that we have evolved mechanisms to enable adaptation to fluctuations in nutrition so as to better fit offspring to their perceived (nutritional) environment, and thus give them a reproductive advantage. This talk will argue that we already have evidence of this from fetal programming studies and from inter-generational effects following experimental manipulation of parental (especially paternal) diet and consequent metabolic changes in resulting offspring. It will be hypothesized that the epigenetic reprogramming of germ cells that occurs during three key life phases (fetal life, post-fertilisation, gametogenesis) provides the means for sensing of the perceived (nutritional) environment so as to induce adaptive epigenetic changes that ultimately alter offspring metabolic function. It will further be argued that an unbalanced, modern Western diet, which is deficient in epigenetically active plant-derived factors (e.g. folate) may have resulted in changes to the epigenome of offspring that lead to adverse metabolic changes which predispose to modern Western diseases. If these hypotheses are true, parental and even perhaps grandparental diet, could have consequences for health of future generations. How important this might be is unknown.