Why do we get fat? Even if it seems like a question whose answer is really really easy, the scientific community is also divided in this, often causing divergences that the mass media echo, so as to create a skein of contradictory information that confuses the population.

Premise: where does our dietary confusion come from
The science journalist Gary Taubes, guru of the ketogenic and low carb diet, has for example entitled a book just like this: “Why we get fat”. The fault, he says and not only him, are carbohydrates.
In Italy, experts such as Berrino, argue that instead the fault is not so much carbohydrates but too many proteins: where people consume a lot of proteins they are even fatter.

Many of these views are based on observational studies: in one country ten inhabitants wear the red jersey, and six of them also have a genetic disease that the other inhabitants do not have. Experts conclude that those wearing the red shirt are more likely to have a genetic disease. People read these studies and identify an enemy in the red jersey. Here, if instead of the red shirt we think of a food, we immediately understand the underlying problem of observational studies related to food. 
You will say: yes, that’s okay, but while there is no correlation between clothing and disease, there can be correlations between food and disease. No doubt. But it is logic that is wrong and at this point, depending on the food you choose, you could have very similar results, because an observational study combines two data together. Whether or not there are any connections between the two data, the study cannot tell, which is why the conclusions are often expressed in the conditional. But the reader is still led to create a causal link between food (= the red shirt) and disease. Many studies linking a particular food to disease are of this type 

FOUR REASONS WHY WE GET FAT
However, can we find at least 4 reasons why we get fat? Yes. 
I’ll list them on page two.