There’s a lot to be said for how far the diet you eat diverges from your ancestral way of eating.
For example, take a recently indigenous-diet population of say, Australian Aborigines or American Indians and introduce the standard western diet. You get an almost instant decline in health. Take someone with a lineage to people who evolved in a tropical climate, eating fruits and other vegetation and compare them to someone whose ancestors ate mostly meat and dairy for most of their history. Different responses.
Also, unhealthy parents will pass on epigenetic traits to their offspring so you see an amplification of diseases over generations.