"Potatoes Make You Fat? Or Omega-6 Makes You Fat?"

I agree with Melissa, it's clearly the omega-6 oils. 

When I decided one day to stop eating them, the weight started falling off, and my carb cravings stopped immediately.  I'd tried low-carb before, and had not been able to overcome the cravings, so this was a big change.

Here's another version of the story from Bloomberg:

"Potato Chips Seen as Culprit in U.S. Weight Gain":

"Putting aside a 1-ounce bag of potato chips each day in favor of yogurt can save almost a pound of weight gain every four years, according to a Harvard University analysis of the dietary habits of 120,000 Americans.


"People in the U.S. add almost 1 pound a year on average, with those who consume lots of potato chips packing on the most weight and yogurt eaters cutting heft, according to the report published yesterday in the New England Journal of Medicine. A daily serving of potato chips over a 20-year period led to an extra 1.69 pounds (0.8 kilograms) every four years, while yogurt helped people lose about 0.82 pounds, the study found..."

My view, however, is that most of these studies are bogus.  Potato chips are deep-fried in omega-6 vegetable oils, and that's what makes people gain weight.  Eat what healthy people have traditionally eaten (which includes potatoes, but does not include industrially-produced omega-6 seed oils), and ignore what the scientists tell you.  Your grandmother is a more reliable source of information, and she has your best interests at heart.