This is an open access paper. Abstract Overfeeding and overeating in families are traditions that are often transferred from generation to generation. Irrespective of these family traditions, food availability might lead to overfeeding, in its turn leading to metabolic adaptations. Apart from selection, could these adaptations to the social environment have transgenerational effects? This study will attempt to answer the following question: Can overeating during a child’s slow growth period (SGP), before their prepubertal peak in growth velocity influence descendants’ risk of death from cardiovascular disease and diabetes? Data were collected by following three cohorts born in 1890, 1905 and 1920 in Överkalix parish in northern Sweden up until death or 1995. The parents’ or grandparents’ access to food during their SGP was determined by referring to historical data on harvests and food prices, records of local community meetings and general historical facts. If food was not readily available during the father’s slow growth period, then cardiovascular disease mortality of the proband was low. Diabetes mortality increased if the paternal grandfather was exposed to a surfeit of food during his slow growth period. (Odds Ratio 4.1, 95% confidence interval 1.33 – 12.93, P=0.01). Selection bias seemed to be unlikely. A nutrition-linked mechanism through the male line seems to have influenced the risk for cardiovascular and diabetes mellitus mortality. Keywords: childhood overeating; slow growth period; transgenerational effects; cardiovascular disease; diabetes mellitus; mortality

Opening Paragraphs: New research has provided evidence for ‘environmental inheritance’, a radical theory of transgenerational genetic adaptation proposed by Professor Marcus Pembrey of the Institute of Child Health, UCL in the mid 1990’s The latest evidence challenges accepted thinking on genetic inheritance, suggesting that historic events can contribute to some common modern illnesses . The research, published by the Children of the 90s study based at the University of Bristol in collaboration with Umeå University, Sweden, could have far-reaching implications for our understanding of modern health epidemics – such as obesity or cardiovascular disease. Conventionally scientists believe that how we develop as adults depends on two factors - the genes (DNA) we inherit from our parents, and the environmental influences, such as diet, lifestyle, exposure to pollution from conception onwards Professor Marcus Pembrey, who is also head of Genetics at Children of the 90s, says that over the long term, the process of Darwinian evolution by random errors in DNA followed by natural selection ensures that the human race adapts to changes in our environment. But it takes very many generations.