I'm not sure how to answer this question, but I will give this anecdote and see if it helps.
There are comparitive differences between my family and grandparents and my boyfriend's family and grandparents (and their health).
I've been thinking about this for quite some time, mind you.
My family is from Argentina. Although in the past 5-10 years things in Argentina have changed, my family that still live in the country grew up eating lots and lots of grilled grass fed red meat, offal, and fat (steaks galore), eggs, olive oil and vinegar in enormous salads, handmade high quality cheeses and salami/deli meats (about 2-3 times a week), plenty of fresh fruits and vegetables, occasional french fries fried in tallow and home made french bread, and the occasional indulgence of a pastry about 1 a week. About once a week there is also a bowl of pasta or a lasagna or some gnocchi, all made by scratch at home, and an occasional but most of what they eat is meat, fish, and salad. Good Wine is daily staple, and much more is drank over the weekends. Carbs are present, but they don't happen every day, steaks do.
My boyfriend's family, however, is different. Most of them have move from either Cape Verde or Portugal within the past 40 years, and have adapted some American ideals along the way as well. They eat lots of potatoes and plain white and multi-grain bread, tons of rice and beans, some meat and fish, and plenty of sodas, simple sugars. Although most of their diet is home made, it still consists of exorbant amounts of simple carbohydrates. Alcohol is usually only on the weekends in the form of straight whiskey or mixed fruity drinks.
Anyhow, the correlation. My family (in Argentina, not so much in America) stays pretty healthy. They play, they relax, they sleep, they walk. Most of them have hot bodies. They don't overeat, and sometimes they do intermittent fasting without thinking about it. They are pretty healthy, especially my super hot 65 year old aunt who looks half her age. She is, in my belief, in optimal shape.
My boyfriend's family, however, on both sides, are stricken with Diabetes that they get later in life, usually when they get in their late 20's. Some are overweight, some aren't; most maintain their weight pretty well, including the older generation, but their health is failing. Their bones break more easily, they don't generally workout (except for a few younger bodybuilding types). There is much more IBS than I've seen in any family. Constipation is a daily issue on both fronts. They have back problems, such as disc herniations, and sad and scary things like stroke happen at younger ages than they should.
Can it be what you eat that makes a difference in how well oiled your machine is? What do you make of these differences? I'd like to know if there is some research about different parts of the world and how they eat, and how it affects health.