More and more Americans are obese; a piece of news that we rightly know but that can give us the following question, namely: “Yes, but what do we who are Italians care?”. And in fact we wouldn’t give a damn about the American diet, were it not for two reasons that I find fundamental :
– the American diet has influenced the whole West, so much so that we could think of calling today’s American diet a typical “modern diet”.
– obesity in Italy as well as in other European countries has reached alarming levels, in line or almost in line with those in the United States: sure that taking a look at how the American diet has changed in the last forty years will not tell us anything about how Has ours changed since we are gaining weight the same way?

Another important reason why learning more about the correlation between the American diet, obesity and our diet can be helpful is that a lot has to do with the industrialization of food. And so, the statistician Nathan Yau would have used the data from the  Food Availability Data System  to make a dynamic picture of the dietary changes of the last 40 years in America, discovering that :
– from 1970 to 2013, Americans consumed much less whole milk (significantly less) but more “Italian” cheeses, at least 3 times a day. The reason for this preference is simple: pizza. Americans eat a lot of pizza and therefore also a lot of “pizza” cheeses. 
– from 1970 to 2013 the most popular vegetable remained the potato; followed in recent years by green leafy vegetables (salads): before, instead, more tomatoes and legumes were consumed.  
– from 1970 to 2013 the consumption of butter decreased significantly in favor of vegetable oils 
– from 1970 to 2013 the consumption of flour increased slightly, but not as much as one supposes
– from 1970 to 2013 the consumption of beef decreased significantly in chicken favor. 
Do these variations tell us something? If so, this works in favor of the theory that fats don’t get fat, to know how to choose them well. In fact, a decrease in saturated fats did not lead to a tendency to lose weight: whole milk and butter are also sources of fat-soluble vitamins as well as fats; yes, of course, cheeses are too , but if you consume them in pizza (and if the pizza is American) any benefits are eliminated by the excess of carbohydrates. Even a significant increase in vegetable and chicken oils throws a disturbing light on the effect that omega6 fatty acids can have on the waistline of us Westerners: chicken is in fact rich in these polyunsaturated fats, as are mixed vegetable oils.
It would be nice if someone did a similar study in Italy too, to find out if there are any differences, and if and how much Western trends have influenced us on our way of getting fat. A final and most disturbing data concerns calories: the average American consumes about 500 calories more than 40 years ago. Taking into account that in the meantime there has also been a boom in slimming diets, this figure is also strange: in fact, we tend to eat more and more.