It is certainly hard to understand how early life events are leading to later disease. Here is an incredible nutrigenomics story done in agouti mice:

We find that the somatic epigenetic state of A^vy is affected by in utero methyl donor supplementation only when the allele is paternally contributed. Exposure to methyl donor supplementation during midgestation shifts A^vy phenotypes not only in the mice exposed as fetuses, but in their offspring. This finding indicates that methyl donors can change the epigenetic state of the A^vy allele in the germ line, and that the altered state is retained through the epigenetic resetting that takes place in gametogenesis and embryogenesis. Thus a mother’s diet may have an enduring influence on succeeding generations.