@kushchan isn't that because the people there tend to eat what they've eaten for centuries? i have the vague feeling that if you'd eat the traditional everyday food of anywhere in the world you'd be healthy. here it would be whole grain stuff, cheese and milk (not industrially produced), various vegetables, berries, nuts, eggs and mushrooms. won't get fat on that.
@kushchan you won't have had much meat, maybe chicken from time to time. pig stuff for holidays. you get proteins from eggs together with vitamins (notably B12). chicken are the "poor mans pig" :)