Do turtles grow during hibernation

No. When it begins to get cold outside, they strive to eat more and fatten themselves up... Like a bear. When they are in hibernation, their heart, lungs, metabolism, etc slows down dramatically so they can survive without food. Some captive turtles, however, don't go into hibernation because they are kept inside at a reasonable temperature. If this is the case, then they will eat, but most likely not as much as during the summer.