Want to avoid packing on the pounds?  Try cutting back on potato chips.  They are the top culprit for putting on pounds over time, according to a new study from Harvard.  It sounds like a no-brainer, doesn't it? 

Scientists at Harvard looked at the diet and lifestyles of more than 120,000 people and found that what

we consume and how much we consume has a bigger impact on long-term weight gain than how much we exercise.  As they studied what people ate, they determined that potato chips were the biggest culprit for putting on pounds.  Eating 15 chips a day over a four year period led to almost a two pound weight gain.  What is it about potato chips that make them so irresistable?  Obesity expert Dr. Pi-Sunyer says it best: "They're very tasty and they have a very good texture.  People generally don't take one or two chips.  They have a whole bag."   It's hard to eat just one.  Are you surprised chips beat out sweets or fried foods?