Information theory
We know our bodies should have a caloric budget.
We know eating certain foods (leafy greens, high in fiber foods, etc) are good for us.
And we know that eating certain foods (fatty foods, salty foods, sugary snacks, etc) are bad for us.
We carefully determine our caloric intake to maintain a healthy weight, often mixed with some regular exercise.
But what we often forget is that our intellect needs to have a caloric budget too.
And that budget needs to include brain food, in this case, information and ideas, that meet or exceed a minimum daily dose of good information and ideas that make our thoughts strong and agile.
And by extension, minimize the kinds of information and ideas that are too fatty that make us slow and stupid.