Read the following example and determine which type of irony is being used:
As the holiday season ended, Gigi struggled to put on her blue jeans. They seemed much tighter than usual, so she stepped on the weight scale and received the bad news. She had never seen such a high number on the little scale, so she resolved to change. That day she threw out all of the junk food in her fridge and went grocery shopping. She was determined to lose weight, so she bought low-fat and reduced calorie versions of all of her favorite foods. When she got home she had a low-sodium bacon sandwich and a diet soda. For dinner she had two burgers with reduced fat cheese and half-fat mayonnaise, along with two low-calorie ice-cream sandwiches for dessert. Before she went to bed, she ate a bag of baked potato chips, which are healthier than normal chips, and dipped them into low-fat cream cheese. When Gigi woke up the next morning, she was pleased with how well her diet was going, but when she stepped on to the scale, she saw that she had gained a kilogram.