Is this America's number one cause of obesity?

In his book Salt, Sugar Fat, Michael Moss talks about a study that started in 1986.  Its goal was to track the eating habits of Americans.

The study involved 120,877 people who were surveyed every four years.  None of the participants were overweight.  All of participants worked in the health field which presumably made them more nutritionally aware.

Here's what they found and reported in The New England Journal of Medicine in 2011.  Every four years, people tended to exercise less and watch more television.  Plus they gained an average of 3.35 lbs.

The top foods that contributed in the weight gain department were red meat, processed meats, sugar sweetened beverages and potatoes.

But one food outdid all the others in term of contributing to weight gain...

The potato chip!

It was responsible for an average 1.69 lb. weight gain per individual every four years. (Sweets and desserts contributed to about half a pound).

What did they attribute it to?

First off every ounce of potato chips has about 160 calories.  Plus they are loaded with fat, sugar and salt.

But an even bigger factor was, as the old marketing slogan "Betcha Can't Eat Just One" implies, it's nearly impossible to eat just one or two chips per sitting.