If you weigh 15 or 20 pounds more than you did in high school, potato chips could be a big culprit in the slow weight creep over the years.

That's according to a major new diet study from Harvard University scientists.

People often gain weight gradually over decades, and the researchers found that what we eat and how much of it we consume has far more impact than exercise and most other habits on long-term weight gain.

When looking at what people ate, the researchers found that potato chips were the biggest culprit in putting on pounds, with each daily serving of about 15 chips leading to a 1.69-pound weight gain over four years.

I know what the problem with chips is...you truly can't eat just one, unless you are talking about just one bag.

What kind of chips is your downfall?  Taco flavored Doritos are back.  Plus, I love the salt and pepper Kettle Chips, and Cheetos, Pringles and Fritos...Hmmm, that may explain some things.