No, not doughnuts, but instead potato chips. That's the finding of a new diet study from Harvard and Brigham and Women's Hospital.
Data from three separate long-term studies that kept track of participants for 20 years found as they aged they gained an average of 3.35 pounds every four years.
That weight gain was most associated with potato chips, potatoes, sugar-sweetened beverages, and unprocessed and processed meats.
Other factors included alcohol use, quitting smoking and not enough sleep.