In a blog post about whether potatoes are really as bad as implicated in a study published by the New England Journal of Medicine, food-policy doyenne Marion Nestle shares the six most common sources of calories in the American diet:

“Grain-based” desserts (translation: cakes, pies, cookies, cupcakes, etc)
Breads
Chicken and chicken mixed dishes (translation: fingers)
Sodas, energy, and sports drinks
Pizza
Alcoholic beverages

Potato chips are 11th and French fries are 17th.

There are several ways to use this information, but the first that occurs to me is that if you're wanting to reduce your calories, this is the roadmap. Pick one or two of the categories to eliminate, and you'll be making big strides.

Meanwhile, what I notice is that the top 2 are refined grain or refined grain combined with refined sugar. No. 3 essentially is protein as a refined-grain delivery system (how many chicken fingers would be consumed without the yummy oil-drenched flour casing?), and No. 4 is refined sugar.

The significance of this cannot be overstated, no matter how often it is overlooked.